# Week 14 project updates _Exported on 12/14/2025 at 07:30:15 EST from Cursor (2.1.39)_ --- **User** follow the general guidelines: — for each image or video add a caption and description. — make all the text professional and succinct without losing key details — make the information as organized and as aesthetically pleasing as possible — don't just take my notes from the prompt, refine it before putting it on the page
 -- for anything step by step, make the steps clear and easy to follow all the images are in week14/day4 specific tasks: (all in week14.html) 1-- update electrical integration section with the content in this chat (refine it as futuring electrical improvements) -- embed the links as resources found a touchscreen schematic: https://forum.arduino.cc/t/esp32-c3-and-ili9341/1412193/9 touch_screen.png touch_screen.png Arduino Forum ESP32-C3 and ILI9341 Yes. With an ESP32-C3 (super mini) and an ILI9341 with touch screen (as yours but 2.8") using these libraries: Additional notes: The diagram includes backlight brightness and ambient light detection (transistors Q4, Q5 and Q6). For simplicity you can ignore all that and simply power the backlight via a say 100R resistor at 3v3. The TFT screen reset pin is not used and is pulled to 3v3 via a 10k resistor. The diagram shows this incorrectly as pulled to 5v. The touch screen uses t... Nov 4th 11:32 potentially here too https://forum.arduino.cc/t/ili9341-tft-display-in-xiao-esp32-seeeduino-miso-issue/1107577/3 Pin connections: VCC -> 5 V GND -> GND CS -> GPIO3 RST -> GPIO4 DC -> GPIO5 MOSI -> GPIO10 SCK -> GPIO8 LED -> 5 V MISO -> GPIO9 T_CLK -> TFT_SCK T_CS -> GPIO21 T_DIN -> TFT_MOSI T_DO -> TFT_MISO Arduino Forum ILI9341 TFT display in XIAO ESP32 Seeeduino MISO issue Well I'm connecting the tft MISO to the esp MISO. I'm not really defining MISO to GPIO9, so I don't know if I can assign MISO to another pin. I looked in different posts and couldn't find a way of assigning it to another pin. I do found that the MISO pin enters bootloading mode after resetting the device. Mar 27th, 2023 Saleem Aldajani 11:41 AM super cool tangent: https://docs.cirkitdesigner.com/project/published/2b874d09-7d4c-4b53-944e-c6cc824a394c/esp32c3-based-thermal-imaging-camera-with-tft-display docs.cirkitdesigner.comdocs.cirkitdesigner.com ESP32C3-Based Thermal Imaging Camera with TFT Display | Cirkit Designer Explore comprehensive documentation for the ESP32C3-Based Thermal Imaging Camera with TFT Display project, including components, wiring, and code. This project is a thermal imaging camera that utilizes an ESP32C3 microcontroller to process thermal data from a GY-MCU90640 sensor and display it on an ili9341 TFT screen. The camera captures temperature variations and translates them into a visual heat map, which is then rendered on the TFT display for real-time monitoring. Perfect for students, hobbyists, and developers, this project can be opened and customized directly in Cirkit Designer. (327 kB) https://docs.cirkitdesigner.com/project/published/2b874d09-7d4c-4b53-944e-c6cc824a394c/esp32c3-based-thermal-imaging-camera-with-tft-display Saleem Aldajani 2:21 PM always check front and back before milling is the lesson learned in schematic and on the machine in the bantam tools software, i forgot to check back on the machine -- future sources for tft touchscreen wiring to esp32 xiao (put links to the other sources i read too just highlight this one as the one i used for pinout mapping to esp32 xiao) tft touch-esp wiring: https://forum.arduino.cc/t/esp32-c3-and-ili9341/1412193/9 https://forum.arduino.cc/t/ili9341-tft-display-in-xiao-esp32-seeeduino-miso-issue/1107577/3 -- thermal imaging camera https://docs.cirkitdesigner.com/project/published/2b874d09-7d4c-4b53-944e-c6cc824a394c/esp32c3-based-thermal-imaging-camera-with-tft-display embed this images and reference it: https://forum.arduino.cc/t/esp32-c3-and-ili9341/1412193/9 touch_screen_wiring_diagram.png 2-- add a new section for day 4 subsystem integration with these subsections 2.1. 2d fabrication: laser cutting and vinyl cutting laser cut thinner acrylic for better fit of clear display cover for aging clock subsystem, embed these images and videos: aging-clock-clips-nice.jpeg laser-cutting-thin-acrylic.mp4 laser-cutting-thin-acrylic-final.mp4 laser-cutting-1.35mm-acrylic.jpeg laser-cut-success.jpeg laser-cut-success-2.jpeg 2.2. 3d printing rigid and flexible components the band clips were printed out of tpu for better fits, embed these images: filed-inserted-clips.jpeg assembly-clips.jpeg aging-clock-clips.jpeg aging-clock-clips-nice.jpeg 2.3. milling single and double-sided boards i milled the design for tft aging clock and will solder and test today. the first mill had traces that were too close and the rivets were under the microcontroller, so i fixed it by hand with the ultrasonic knife and then had time to mill the fixed board at the end of the end when everybody finished, embed these images and videos: mill1-front.mp4 mill1-locate-tool-1.mp4 mill1-front-start.mp4 mill1-locate-tool-2.mp4 mill1-front-start-2.mp4 mill1-back-start.mp4 mill1-back-start-2.mp4 mill1-back-start-3.mp4 mill1-unloading.mp4 mill1-vacuuming.mp4 removing-milled-pcb.jpeg first-side.jpeg missing-traces.jpeg missing-trace-1.jpeg missing-traces-2.jpeg double-sided-mills-1.jpeg sonic-saber-ultrasonic-knife.jpeg utility-knife.jpeg cut-trace-1.jpeg trace-1-cut.jpeg cut-trace-2.jpeg trace-2-cut.jpeg agingclock_board_v1_front.jpeg agingclock_board_v1_back.jpeg tft-fits.jpeg tft-fits-2.jpeg milling3-agingclock-front-1.mp4 milling3-agingclock-front-2.mp4 milling3-agingclock-front-3-locate-tool.mp4 milling3-agingclock-front-4-start.mp4 milling3-agingclock-front-4-tool2.mp4 milling3-agingclock-back-1.mp4 milling3-agingclock-back-2-start.mp4 milling3-agingclock-back-3-start.mp4 milling3-agingclock-vacuuming.mp4 aging_clock_tft_moved_rivets.jpeg aging_clock_tft_moved_rivets_nice.jpeg aging_clock_tft_moved_rivets_holes.jpeg i remilled the base amplifier board that failed yesterday due to polygon pour isolate default set to 0 again after we changed it to 32 on the back and it worked. i also milled the upgraded board to include a tft screen, and now i can solder and test both depending on how much time there is. embed these images and videos: mirrorage_board_v1_front.jpeg mirrorage_board_v1_back.jpeg mirrorage-tft-milling-front.mp4 mirrorage-tft-milling-front-2.mp4 mirrorage-tft-milling-back-1.mp4 missing-trace-1-mirrorage-tft.jpeg mirrorage_tft_front.jpeg double-sided-taping.jpeg mirrorage_tft_worked.jpeg mirrorage_tft_back.jpeg mirrorage_tft_back_nice.jpeg 2.4. molding and casting starting from Anthony's sketch in my midterm review, i designed 3d-printable open molds to cast the watch bands out of moldstar 30. i printed them out of PLA, waxed them, mixed molds, poured, leveled, then moved under lamp for curing, demolded, then tested they fit into each other. i needed to cut out the center part of the printed mold for the part to be removable with an ultrasonic knife before pouring. for backup, i printed an final tpu band since one print failed last time. embed these images and videos: midterm_review_sketch_anthony.jpeg printed-mold-a.jpeg printed-mold-b.jpeg printed-molds.jpeg wax-melting.mp4 wax-melting-2.mp4 wax-painting.mp4 mold-a-cutting-waxing.jpeg mold-b-cutting-waxing.jpeg wax-thinning.mp4 waxed-casting-ready.jpeg a-b-mixing.jpeg mixing-mold.mp4 stirring-mixed-molds.mp4 a-b-mixed.jpeg pouring-1.mp4 poured.jpeg leveling-liquid.mp4 leveling-liquid-2.mp4 level.jpeg heat-lamp-curing.jpeg heat-lamp-curing-2.jpeg demolding-1.mp4 demolding-2.mp4 demolding-tabs.mp4 band-testing.mp4 2.4. aging clock subsystem fabrication tft aging clock board was assembled into the watch enclosure and it fit! embed this image: aging-clock-assembly.jpeg 3. go through week14/system_integration_design_files folder by folder and file by file and put a big table in design files for all the design files that were used so far, include a short title name for the file, brief description, category, link to where it was used on the page if available, and link to download 4. update critical path analysis based on what we have done in the page so far after fully updating tasks 1 and 2 and 3 --- **Cursor** Reviewing the current structure and gathering the necessary files. Searching for the electrical integration and critical path sections: Reading the relevant sections: Searching for the Day 3 section to determine where to add Day 4: Creating a todo list and starting the updates: Updating the electrical integration section with touchscreen wiring and future improvements: ```html Week 14 · Final Project
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Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled ✓
  • PCB milling: MirrorAge board (base and TFT versions ready for milling)
  • PCB milling: TFT-integrated aging clock board (design complete, ready for milling)
  • Component soldering (pending board milling completion)
  • Band mold printing and casting
  • 3D printing of board cases (casing, dock, bands) ✓
  • 2D subtractive: laser-cut acrylic display ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Finding where Day 3 ends to add the Day 4 section: Finding the end of Day 3: Adding the Day 4 section before the Critical Path section: ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled ✓
  • PCB milling: MirrorAge board (base and TFT versions ready for milling)
  • PCB milling: TFT-integrated aging clock board (design complete, ready for milling)
  • Component soldering (pending board milling completion)
  • Band mold printing and casting
  • 3D printing of board cases (casing, dock, bands) ✓
  • 2D subtractive: laser-cut acrylic display ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Updating the table of contents to include Day 4, then creating the design files table: ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled ✓
  • PCB milling: MirrorAge board (base and TFT versions ready for milling)
  • PCB milling: TFT-integrated aging clock board (design complete, ready for milling)
  • Component soldering (pending board milling completion)
  • Band mold printing and casting
  • 3D printing of board cases (casing, dock, bands) ✓
  • 2D subtractive: laser-cut acrylic display ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Creating the design files table. Reviewing the design files structure: Adding the design files section before the Critical Path section: ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled ✓
  • PCB milling: MirrorAge board (base and TFT versions ready for milling)
  • PCB milling: TFT-integrated aging clock board (design complete, ready for milling)
  • Component soldering (pending board milling completion)
  • Band mold printing and casting
  • 3D printing of board cases (casing, dock, bands) ✓
  • 2D subtractive: laser-cut acrylic display ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Updating the critical path analysis based on completed work: Finding and updating the critical path section: Finding the critical path section: Updating the critical path analysis to reflect Day 4 progress: ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled ✓
  • PCB milling: MirrorAge board (base and TFT versions ready for milling)
  • PCB milling: TFT-integrated aging clock board (design complete, ready for milling)
  • Component soldering (pending board milling completion)
  • Band mold printing and casting
  • 3D printing of board cases (casing, dock, bands) ✓
  • 2D subtractive: laser-cut acrylic display ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, aging clock board milling, TFT display wiring documentation, fabrication integration testing

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

MirrorAge board milling (base and TFT versions), TFT-integrated aging clock board milling, component soldering, physical integration (mounting holes, power routing), data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, band mold printing and casting, firmware integration, WiFi/MQTT network setup, system wiring, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board with TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Checking for linting errors: ## Completed tasks 1. **Updated Electrical Integration Section** - Added touchscreen wiring information for future improvements - Embedded touchscreen wiring diagram image - Added pin mapping tables for touchscreen integration - Included reference links to Arduino Forum posts and the thermal imaging camera project - Added notes about PCB design checks and MISO pin considerations 2. **Added Day 4 Subsystem Integration Section** - **2.1 2D Fabrication**: Laser cutting thin acrylic (1.35mm) with images and videos - **2.2 3D Printing**: TPU band clips with assembly images - **2.3 Milling**: Single and double-sided board milling with: - First milling attempt documentation - Design issues and manual fixes with ultrasonic knife - Corrected board remilling process - MirrorAge TFT board milling - All associated images and videos - **2.4 Molding and Casting**: Band mold design, printing, waxing, mixing, pouring, curing, and demolding with all process videos - **2.5 Aging Clock Subsystem Fabrication**: Final assembly documentation 3. **Created Design Files Table** - Organized by category (PCB Design, 3D Design, 2D Design, Code Files, Reference Files) - Includes file names, descriptions, categories, usage locations, and download links - Covers all major design files from the system_integration_design_files folder 4. **Updated Critical Path Analysis** - Marked completed tasks from Day 4 (band mold design, all board milling, band casting, etc.) - Updated status sections to reflect current progress - Updated "In Progress" and "Upcoming" sections accordingly All content follows the guidelines: professional and succinct text, clear captions and descriptions for all media, organized structure, and easy-to-follow step-by-step processes. No linting errors were found. --- **User** add this .step file 3006 MAX98357.step above max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download --- **Cursor** Adding the STEP file entry above the existing MAX98357A entry in the Reference Design Files section. Adding the STEP file entry above the existing MAX98357A entry: ```html Week 14 · Final Project
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Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board before TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board before TFT display integratio showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
3006 MAX98357.step STEP file for MAX98357A amplifier reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Fixing the typo in the caption: ```html Week 14 · Final Project
← Back to Home
Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Project Overview

Development

Documentation

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board before TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board before TFT display integration showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
3006 MAX98357.step STEP file for MAX98357A amplifier reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Resources and Documentation

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

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Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

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Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Added the "3006 MAX98357.step" entry to the design files table, placed above the "max98357a adafruit.SLDPRT" entry in the Reference Design Files section. Also fixed the typo in the MirrorAge TFT Back caption ("integratio" → "integration"). The new entry includes: - File name: 3006 MAX98357.step - Description: STEP file for MAX98357A amplifier reference - Category: 3D Model - Used in: Reference - Download link to the correct file path No linting errors found. --- **User** add a subsectionsection 2.0 final electrical design upgrades before 2.1 2.1 2D Fabrication: Laser Cutting and Vinyl Cutting under the Day 4: Subsystem Integration Quote from Quentin ‘you have to get used to rotating it in your head’ since the milling machine wasn't available, i used the time to upgrade my designs, which required rotations of components etc. for them all to fit. embed these images (in week14/day4) mirrorage-tft-front-v13 mirrorage-tft-back-v13 agingclock-tft-front-v16 agingclock-tft-back-v16 --- **Cursor** Adding the "2.0 Final Electrical Design Upgrades" subsection before "2.1 2D Fabrication" in the Day 4 section. Locating the insertion point: Searching for the start of section 2.1: Adding the new section 2.0 before section 2.1: ```html

2.0 Final Electrical Design Upgrades

With the milling machine unavailable, the time was used to upgrade board designs, requiring component rotations and layout optimizations to ensure all components fit properly. As Quentin noted, "you have to get used to rotating it in your head"—a valuable skill for PCB design where spatial reasoning is essential for component placement and routing.

"you have to get used to rotating it in your head" — Quentin

MirrorAge TFT Board Upgrades (v13)

The MirrorAge TFT board design was upgraded to version 13, with component rotations and layout optimizations to improve fit and routing efficiency.

MirrorAge TFT board front side version 13
MirrorAge TFT Front v13: Upgraded front-side layout with optimized component placement and routing
MirrorAge TFT board back side version 13
MirrorAge TFT Back v13: Upgraded back-side routing with improved trace layout and component positioning

Aging Clock TFT Board Upgrades (v16)

The aging clock TFT board design was upgraded to version 16, incorporating component rotations and layout refinements to ensure proper fit within the watch casing constraints.

Aging clock TFT board front side version 16
Aging Clock TFT Front v16: Upgraded front-side design with rotated components for optimal fit
Aging clock TFT board back side version 16
Aging Clock TFT Back v16: Upgraded back-side routing with improved component placement

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

``` Including more context to make the replacement unique: ```html Week 14 · Final Project
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Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.0 Final Electrical Design Upgrades

With the milling machine unavailable, the time was used to upgrade board designs, requiring component rotations and layout optimizations to ensure all components fit properly. As Quentin noted, "you have to get used to rotating it in your head"—a valuable skill for PCB design where spatial reasoning is essential for component placement and routing.

"you have to get used to rotating it in your head" — Quentin

MirrorAge TFT Board Upgrades (v13)

The MirrorAge TFT board design was upgraded to version 13, with component rotations and layout optimizations to improve fit and routing efficiency.

MirrorAge TFT board front side version 13
MirrorAge TFT Front v13: Upgraded front-side layout with optimized component placement and routing
MirrorAge TFT board back side version 13
MirrorAge TFT Back v13: Upgraded back-side routing with improved trace layout and component positioning

Aging Clock TFT Board Upgrades (v16)

The aging clock TFT board design was upgraded to version 16, incorporating component rotations and layout refinements to ensure proper fit within the watch casing constraints.

Aging clock TFT board front side version 16
Aging Clock TFT Front v16: Upgraded front-side design with rotated components for optimal fit
Aging clock TFT board back side version 16
Aging Clock TFT Back v16: Upgraded back-side routing with improved component placement

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board before TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board before TFT display integration showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
3006 MAX98357.step STEP file for MAX98357A amplifier reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

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``` Added the new section "2.0 Final Electrical Design Upgrades" before "2.1 2D Fabrication" in the Day 4 section. The new section includes: 1. **Introduction** explaining that the milling machine was unavailable, so time was used to upgrade board designs with component rotations 2. **Quentin's quote** in a highlighted box: "you have to get used to rotating it in your head" 3. **MirrorAge TFT Board Upgrades (v13)** subsection with front and back images 4. **Aging Clock TFT Board Upgrades (v16)** subsection with front and back images All four images are embedded with captions describing the design upgrades. The section follows the same styling and structure as the other Day 4 subsections. No linting errors were found. --- **User** — run the commits and pushes in small <25mb packets to avoid the limit (make sure to push and sync changes with each small commit because the limit is at the sync in the end). Don’t use ffmpeg everything is already compressed, just one file at a time if they are large --- **Cursor** Checking git status and file sizes to commit and push in small batches (<25MB). Checking sizes of the new directories and files: Committing in small batches. Starting with the HTML file, then processing the directories in batches: Committing directories in small batches. Listing files and grouping them: Committing image files first, then videos. Starting with the first batch of images: Committing videos in small batches, one or two at a time: Continuing with wax and milling videos: Continuing with the remaining milling videos: Checking for remaining files in week14/day4, then moving to system_integration_design_files: All Day 4 files are committed. Committing system_integration_design_files in batches, starting with smaller files: Adding the remaining 3MF and other files individually: Committing the remaining KiCad PCB design files and code directories: Committing the remaining file: All files have been committed and pushed in small batches (<25MB per commit). Summary: ## Commits Summary: 1. **week14.html** - Updated HTML file with Day 4 content 2. **Day 4 Images** - All 53 image files (JPEG/PNG) in one commit 3. **Day 4 Videos** - Committed in small batches (1-2 videos per commit): - Band testing and demolding videos - Leveling and mixing videos - Wax application videos - Laser cutting videos - Milling process videos (first attempt, corrected boards, MirrorAge board) 4. **System Integration Design Files** - Committed by category: - Laser cutter files - Mold design files - 3D model files (bands, dock, watch body) - Reference component files (SSD1306, XIAO, MPU6050, MAX98357A, ILI9341) - KiCad PCB design files (QPAD21, QPAD XIAO ESP32S3) - Final PCB board files - Backup and clip files All commits were pushed immediately after creation to sync with the remote, keeping each commit under 25MB. The working tree is clean and all changes are synced. --- **User** in 'Design Issues and Manual Fixes', mention that the ultrasonic knife was used to initiate the cuts on both ends of the missing trace, then a utility knife was used to cut a straight line between them. the challenge is controlling the first penetration with the utility knife, so the the ultrasonic knife really helped with cutting the initial penetration direction right so the utility knife cut was smooth and easier from end to end to isolate the upper and lower wiring this comes right after 'After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using an ultrasonic knife before remilling the fixed design.' make it fit into context of course and flow well --- **Cursor** Locating the "Design Issues and Manual Fixes" section to add details about the trace cutting process: Adding details about the trace cutting process: ```html Week 14 · Final Project
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Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.0 Final Electrical Design Upgrades

With the milling machine unavailable, the time was used to upgrade board designs, requiring component rotations and layout optimizations to ensure all components fit properly. As Quentin noted, "you have to get used to rotating it in your head"—a valuable skill for PCB design where spatial reasoning is essential for component placement and routing.

"you have to get used to rotating it in your head" — Quentin

MirrorAge TFT Board Upgrades (v13)

The MirrorAge TFT board design was upgraded to version 13, with component rotations and layout optimizations to improve fit and routing efficiency.

MirrorAge TFT board front side version 13
MirrorAge TFT Front v13: Upgraded front-side layout with optimized component placement and routing
MirrorAge TFT board back side version 13
MirrorAge TFT Back v13: Upgraded back-side routing with improved trace layout and component positioning

Aging Clock TFT Board Upgrades (v16)

The aging clock TFT board design was upgraded to version 16, incorporating component rotations and layout refinements to ensure proper fit within the watch casing constraints.

Aging clock TFT board front side version 16
Aging Clock TFT Front v16: Upgraded front-side design with rotated components for optimal fit
Aging clock TFT board back side version 16
Aging Clock TFT Back v16: Upgraded back-side routing with improved component placement

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using a two-step cutting process: the ultrasonic knife was used to initiate precise cuts on both ends of each problematic trace, establishing the correct penetration direction. A utility knife was then used to cut a straight line between these initiation points, isolating the upper and lower wiring. The challenge with manual trace cutting lies in controlling the initial penetration with the utility knife—the ultrasonic knife's precision in establishing the cut direction made the subsequent utility knife cut smoother and easier to complete from end to end. After these manual corrections, the board design was updated and remilled with the fixed layout.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Tool used for precise trace cutting and board modification
Utility knife for board modifications
Utility Knife: Additional tool for manual board corrections
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board before TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board before TFT display integration showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
3006 MAX98357.step STEP file for MAX98357A amplifier reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

© Saleem A. Al Dajani
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Saleem A. Al Dajani

Week 14

System Integration

Week Highlights

Final project integration week focused on bringing together all subsystems into a cohesive MirrorAge system, completing documentation, and preparing for final presentation.

Table of Contents

Week 14 System Integration

Final integration week focused on bringing all subsystems together, completing hardware fabrication, firmware integration, and documentation for the MirrorAge system presentation.

Week 14 Day-by-Day System Integration Plan

Positive Possum encouragement meme

Theme of the Week

FINITIATIVE

The act of bringing something to a conclusion or ending in a decisive manner. The ability to efficiently finish tasks and projects with a goal-oriented mindset.

Wednesday

Morning
  • Publish system integration plan on website
  • Update weekly assignment sections on final project page (weeks 10-13)
  • Link final project design files
  • Update reflections and learnings
  • Update picture of prism holder
  • Add final pictures to Slack canvases
  • Create schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Start CAD model of system
  • Place final order
Afternoon & Evening
Design:
  • Boards: Combine OLED screen/accelerometer with pulse oximeter board in a new board (maybe upgrade to small TFT as minor)
  • Boards: Speaker board with realtime amplifier and TFT (on the load cell fixed board)
  • Band: Mold design
  • Cases: 3D print mountable cases for the boards
  • Integrate designs into final CAD
  • Document design
  • Finish CAD model of system

Thursday

Fabricate
  • Milling boards
  • Print mold and cast band
  • Print cases
Solder
  • Solder components on milled boards
  • Connect boards with wired (and wireless connection codes)
Finishing
  • Mirror on screen (easy way with the film)
Documentation
  • Document fabrication

Friday

Programming
  • Board level codes
  • Server level codes
Documentation
  • Document codes
Completion
  • Finish anything else

Saturday

Programming & Testing
  • Demo integrated system
  • Test integrated system
Documentation
  • Document testing and evaluation
  • Review and complete documentation (list of questions)
  • Make the video by collaging documentation

Sunday

  • Fill up any gaps
  • Prepare demo on tensegrity table
  • Finalize 1-slide
  • Work on minors
  • If done, work on if there's time

Monday Morning

  • Transport demo on tensegrity table
  • Fill up any gaps
  • Work on minors

Specific Tasks to Complete This Week

Major Tasks
  • CAD model of system
  • Speaker board with realtime amplifier
  • Combine screen/accelerometer with pulse oximeter board in a new board
  • Mold and cast band
  • Design and fabricate casing (print)
  • Schematic between boards (wired and wireless) — updated system diagram on PPT-like page
  • Serial connection between pulse oximeter and tiny blinking heart for BPM (BPM from IR, SpO2 from delta)
  • Combine multiple boards on the same WiFi (switching tabs is easy way, board hosting the webpage querying and update or Python-based server somewhere where everything posting data, Raspberry Pi)
  • Put+program everything together according to the above (with WiFi for now)
  • Mirror on screen (easy way with the film)
  • Document evaluations and costs (plus the rest of the list here: project presentation requirements)
  • Summary slide and one-minute video for documentation
    • Conception
    • Construction
    • Operation
Minor Tasks
  • Program microphone/speaker
  • Fix reaction time delay code
  • Program LoRa connection
  • Fix OLED plus WiFi issue
  • Upgrade to TFT (SPI is very straightforward, design board with either SPI or OLED connection)
  • Fix heart engraving to center
  • Engrave K9 glass mirror if it arrives
  • RD and IRD isolation slit (maybe wick and then cut)
  • Do the calibration curve for the load cell
  • Finish cardboard laser cutter origami big mirror frame
If There's Time
  • Moving base of mirror
Orders
  • Raspberry Pi Zero (or server host, do some research)
Presentation
  • Aim for 2.5 minutes because Neil will ask questions
  • Generally no slides except for 1 open summary slide (have backup slides in case questions come up!)

Related: See the Development Timeline on the final project page for the overall project schedule.

Day 1: Design Integration

Initial system integration work focused on subsystem validation, CAD model consolidation, and design backbone acquisition for band integration.

Subsystem Validation

Conducted comprehensive testing of all subsystems to ensure proper functionality. Identified and resoldered any defective joints, verifying that each subsystem operates correctly before proceeding with full system integration.

CAD Model Consolidation

Exported CAD models of all PCBs in the final design and imported them into a unified CAD assembly. This consolidated model provides a complete view of the system's mechanical integration and spatial relationships.

Exploded isometric view of the integrated CAD model showing all PCBs, housing components, and wearable band assembly
Integrated CAD Model: Exploded isometric view of the complete system assembly, including all PCBs (pulse oximeter, OLED/accelerometer, speaker/amplifier), main housing with transparent enclosure, and wearable band components. The model shows the spatial relationships between electronic subsystems and mechanical structures, enabling precise integration planning.

Band Design Backbone

Acquired CAD design files for Apple Watch form factor integration, enabling compatibility with existing band designs and standardized watch components. This provides a proven mechanical foundation for the wearable subsystem.

Apple Watch Form Factor: MutantW v2 Project · Instructables Guide
Apple Watch Band Design: Thingiverse Band Files

Next Steps

Resuming the daily schedule tomorrow with parallel work streams prioritized according to the critical path. Tasks that cannot be completed during scheduled days will be shifted to buffer days on Saturday and Sunday to maintain project momentum.

Day 2: Electrical and Mechanical Integration

Physical integration of subsystems into the complete demo table assembly, including mechanical component fabrication and electrical board consolidation.

2.1 Mechanical Integration

Mechanical design integration now includes the complete demo table with precise placement of the MirrorAge handgrip subsystem and the aging clock subsystem. The integrated assembly provides a unified platform for system demonstration and testing.

Complete demo table assembly showing integrated MirrorAge handgrip and aging clock subsystems
Complete Demo Table Assembly: Integrated mechanical design showing precise placement of the MirrorAge handgrip subsystem and aging clock subsystem on the demo table. The assembly demonstrates the spatial relationships and mounting configurations for both subsystems within the unified demonstration platform.

3D Additive Manufacturing

All 3D additive mechanical components were printed for rapid iterative development. The fabrication process required specific print settings and support strategies for different components:

Printing Initiation: 3D printer starting the fabrication process for mechanical components
3D printed casing component during fabrication
Casing Print: Casing component during 3D printing process
Print Configuration Requirements:
  • Casing: Required organic support structures for complex overhangs
  • Dock: Required brim adhesion to prevent warping during printing
  • Bands: Printed using TPU (Thermoplastic Polyurethane) material for flexibility (will spiral into molding and casting in future iterations)
Organic support structure configuration for casing print
Organic Support Configuration: Slicer settings showing organic support structures for the casing component
Brim addition to dock component for improved bed adhesion
Brim Addition: Dock component with brim added to prevent warping during printing
Casing component with organic support structures
Casing with Organic Support: Printed casing component showing organic support structures
TPU bands printed for flexible wearable components
TPU Bands: Flexible wearable band components printed using TPU material
Print Failures and Iteration
Failed casing print showing print quality issues
Failed Casing Print: Initial casing print failure requiring support structure adjustments
Failed dock print showing warping issues
Failed Dock Print: Dock print failure due to warping, resolved with brim addition
Collection of printing failures and debugging process
Printing Failures: Documentation of various print failures encountered during iterative development
Successful printing progress showing completed components
Printing Progress: Successful components showing iterative improvement in print quality

2D Subtractive Manufacturing

The first 2D subtractive mechanical component was debugged and fabricated. The display face component required exporting a DXF of the full face to laser cut an acrylic display that fits the casing precisely. The original display part face was too small because it was filleted, so the edges of the aging clock body were traced and exported for accurate laser cutting.

Laser Cutting Process 1: Initial laser cutting of acrylic display component
Laser Cutting Process 2: Continued laser cutting operation for display face
Acrylic display component fitted into casing
Acrylic Display Fit: Laser-cut acrylic display component precisely fitted into the casing, demonstrating successful integration of 2D subtractive and 3D additive manufacturing components.

2.2 Electrical Integration Methods to Spirally Develop

Electrical design integration combines multiple subsystems into unified board designs, with progressive upgrades incorporating TFT displays for enhanced visual feedback. The integration follows a spiral development approach, starting with base designs and iteratively adding features like TFT displays as design constraints are validated.

Board Design Evolution

Initial board design showing size constraints
Initial Board Design: First integrated board design showing size constraints relative to casing dimensions
Board design fitted within casing constraints
Board in Casing: Revised board design fitted within casing dimensional constraints
Final integrated aging clock board design
Final Integrated Board Design: Complete aging clock board design combining accelerometer/camera functionality with pulse oximeter sensors in a single unified PCB layout optimized for casing fit and component placement.

TFT Display Integration

Both the aging clock watch board and the MirrorAge load cell-speaker board have been upgraded to include TFT displays for enhanced visual feedback. The displays use SPI communication for straightforward integration with the ESP32-S3 XIAO microcontroller.

TFT to ESP32-S3 XIAO Pin Mapping:

Based on the Seeed Studio XIAO ESP32-C3 ILI9341 wiring guide, adapted for ESP32-S3 XIAO:

TFT Pin ESP32-S3 XIAO Pin
VCC 3V3 or 5V
GND GND
CS D0
RST D2
DC/RS D1
SDI (MOSI) D10
SCK D8
LED (Backlight) 3V3

Note: For both 1.8" and 2.4" TFT displays, the LED backlight pin connects to 3V3. Additional references: 1.8" TFT Guide, 2.8" ILI9341 Guide, ESP32-S3 ILI9341 Guide

Future Improvement: TFT Touchscreen Integration

For future iterations incorporating touchscreen functionality, the ILI9341 TFT with integrated touch controller requires additional pin connections. The touch controller shares the SPI bus with the TFT display and uses a separate chip select pin.

TFT touchscreen wiring diagram for ESP32-C3
Touchscreen Wiring Diagram: Schematic showing ILI9341 TFT with touch controller connections to ESP32-C3, adapted from Arduino Forum ESP32-C3 and ILI9341. The diagram includes backlight brightness control (transistors Q4, Q5, Q6) which can be simplified to a 100Ω resistor for basic operation.
Touchscreen Pin Mapping (ESP32 XIAO):
Touch Pin ESP32 XIAO Pin
T_CLK SCK (GPIO8/D8)
T_CS GPIO21/D21
T_DIN MOSI (GPIO10/D10)
T_DO MISO (GPIO9/D9)

Important Notes:

  • The TFT reset pin can be pulled to 3V3 via a 10kΩ resistor (not 5V as sometimes shown in diagrams)
  • The touch controller uses the same SPI bus as the TFT display, requiring a modified XPT2046_Touchscreen library with reduced SPI clock speed
  • MISO pin (GPIO9) enters bootloading mode after reset—ensure proper initialization sequence
  • Always verify front and back of PCB designs in Bantam Tools software before milling to avoid trace clearance issues

Reference Resources:

1.8 inch TFT display for watch board
1.8" TFT Display: ST7735 controller, 128×160 pixels, for aging clock watch board integration
2.4 inch TFT display for load cell speaker board
2.4" TFT Display: ILI9341 controller, 320×240 pixels, for MirrorAge load cell-speaker board integration
TFT display wiring diagram showing pin connections
TFT Display Wiring: Pin connection diagram showing SPI interface connections between TFT displays and ESP32-S3 XIAO microcontroller for both watch and MirrorAge boards.

MirrorAge Amplifier Board Design

The MirrorAge amplifier board integrates a real-time audio amplifier with load cell interface and TFT display. The base design includes the amplifier circuit and HX711 load cell interface, with an upgraded version adding the 2.4" ILI9341 TFT display.

Base MirrorAge amplifier board design
Base Amplifier Board: Initial design with real-time amplifier and HX711 load cell interface
Base MirrorAge board PCB layout
Base Board Layout: PCB layout showing component placement for amplifier and load cell interface
TFT Display Component:

1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model

MirrorAge board with TFT display integration
TFT-Integrated MirrorAge Board: Upgraded PCB design incorporating the 2.4" ILI9341 TFT display alongside the amplifier and load cell interface, enabling visual feedback for grip strength measurements.

Aging Clock Watch Board Design

The aging clock watch board combines pulse oximeter sensors, accelerometer, and camera functionality. The base design uses an OLED display, with an upgraded version incorporating a 1.8" ST7735 TFT display for enhanced visual feedback.

Aging clock watch board base design
Base Aging Clock Board: Initial design integrating pulse oximeter, accelerometer, and camera with OLED display for wearable watch form factor.

Board Fabrication and Integration

The first version of the aging clock board was milled. The initial board did not fit the casing, requiring either casing adjustment and reprinting, or milling a new miniaturized board with shrunken electronics. Both approaches are being evaluated. The MirrorAge board design has been completed for both base and TFT-integrated versions, ready for milling and testing.

Milled integrated aging clock board showing component placement
Milled Integrated Board: First version of the integrated aging clock board after PCB milling, showing component placement and routing
Board nearly fitting in casing showing dimensional constraints
Board Fit Test: Milled board nearly fitting in casing, demonstrating the need for dimensional optimization
Board Deflection Fixing: Process of addressing board deflection and mechanical fit issues during integration testing, demonstrating iterative refinement of the electrical-mechanical interface.

Day 3: Fabrication Integration

Comprehensive fabrication integration work combining 2D laser cutting, 3D printing, and PCB milling to create fully integrated subsystems ready for assembly and testing.

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

The laser-cut acrylic display component was updated in Day 2 and successfully integrated into the watch assembly. The acrylic display provides a clear protective face for the aging clock watch, precisely fitted to the casing dimensions.

The integrated watch assembly demonstrates successful integration of 2D subtractive manufacturing with 3D printed components, creating a cohesive mechanical structure for the wearable subsystem.

2.2 3D Printing: Rigid and Flexible Components

All 3D printed components were fabricated using both rigid and flexible materials. The bands were printed using TPU (Thermoplastic Polyurethane) for flexibility, while rigid components used standard PLA/PETG materials. Additional print details and configuration requirements are documented in Day 2.

The case should also be printed from TPU to improve interlock part fit. The spring-loaded interlock mechanism enables secure band closure while maintaining flexibility for comfortable wear.

TPU band component printed for flexible wearable
TPU Band Print 1: Flexible wearable band component printed using TPU material for comfort and durability
TPU band component showing flexibility
TPU Band Print 2: Flexible band component demonstrating material properties and print quality
Band closure mechanism showing interlock design
Band Closure: Interlock mechanism enabling secure band closure for wearable integration
Rigid dock component for board mounting
Rigid Dock: 3D printed dock component for secure board mounting and electrical connection
Assembled rigid dock with board integration
Assembled Rigid Dock: Complete dock assembly showing board integration and mechanical mounting
Spring-loaded interlock mechanism detail
Spring-Loaded Interlock: Detailed view of the interlock mechanism enabling secure yet flexible band closure
Spring-Loaded Interlock Operation: Demonstration of the interlock mechanism in action, showing secure closure and release functionality for the wearable band system.

2.3 Milling: Single and Double-Sided Boards

Aging Clock Watch Board

The aging clock watch board was successfully milled. The base design with OLED display worked correctly, and the design has been upgraded to include a TFT display. The new TFT-integrated design will be milled and tested alongside the base OLED version to validate both display options.

Milling Process 1: Initial milling operation for aging clock watch board
Tool probing and Z-axis calibration
Tool Probing: Z-axis calibration and tool location setup for precise milling depth control
Milling Process 2: Continued milling operation showing tool path execution
Milling Process 3: Final milling passes completing board fabrication
Completed Milling: Finished aging clock board after successful milling operation
Vacuuming Debris: Post-milling cleanup process removing copper and substrate debris
Removing completed aging clock board from mill
Board Removal: Completed aging clock watch board removed from milling machine, ready for component soldering and testing.

MirrorAge Amplifier Board

The base MirrorAge amplifier board milling initially failed due to polygon pour isolation settings. The default isolation distance was set to 0 mil, which caused routing issues. After changing the back-side polygon pour isolation to 32 mil, the milling operation succeeded. When the shop closed, the design was upgraded to include a TFT screen. Both the base design and TFT-integrated versions will be milled together and tested.

Milling Process 1: Initial MirrorAge board milling operation
Milling Process 2: Continued milling showing tool path execution
Failed milling showing polygon pour isolation issue
Failed Milling: Initial milling failure caused by polygon pour isolation set to 0 mil
Failed Milling Video: Demonstration of milling failure due to incorrect isolation settings
Fixturing board for second-side milling
Second-Side Fixturing: Board secured for double-sided milling operation
Second-Side Milling: Back-side milling operation for double-sided board
Back-Side Milling: Completing double-sided board fabrication
Fixed polygon pour isolation setting at 32 mil
Fixed Isolation Setting: Polygon pour isolation corrected to 32 mil for proper routing
Successful Milling with Fixed Settings: MirrorAge board milling operation completing successfully after correcting polygon pour isolation to 32 mil, demonstrating the importance of proper PCB design rule configuration.

2.4 Integrating Fabrication

Physical integration of fabricated components demonstrates successful coordination between mechanical and electrical subsystems. The watch board fits within the watch case, and the acrylic display integrates properly. Additional work remains for drilling mounting holes for electronics and routing power connections.

Aging clock watch integration showing board and case fit
Aging Clock Integration: Watch board and case integration showing proper dimensional fit
Integrated watch board within case assembly
Integrated Watch Board: Complete watch board assembly within case, demonstrating successful mechanical integration
Assembled bands with clip mechanism
Assembled Bands: Complete band assembly with clip mechanism for secure attachment
Spring-loaded interlock mechanism in integrated assembly
Interlock Mechanism: Spring-loaded interlock providing secure yet flexible band closure
Interlock Operation: Demonstration of spring-loaded interlock mechanism enabling secure band closure and release for comfortable wearable integration.

TFT Display Upgrades

Both board designs have been upgraded to include TFT displays, and integration testing confirms proper fit. The TFT watch board fits correctly with the TFT display, and both the base and TFT-integrated MirrorAge load cell-speaker boards fit within the gripper enclosure. Additional work is needed for drilling mounting holes and adding hooks for load cell wire routing to the HX711 mounted on the board, as well as routing power connections.

Upgraded aging clock board with TFT display
TFT Aging Clock: Upgraded aging clock board design incorporating 1.8" ST7735 TFT display
TFT aging clock board PCB layout
TFT Board Layout: PCB layout showing TFT display integration with existing components
TFT aging clock board schematic
TFT Board Schematic: Electrical schematic showing TFT display connections and component integration
Upgraded MirrorAge board with TFT display
TFT MirrorAge Board: Upgraded MirrorAge board design incorporating 2.4" ILI9341 TFT display
TFT MirrorAge board schematic
TFT MirrorAge Schematic: Electrical schematic showing TFT display integration with amplifier and load cell interface
Integrated demo system showing all subsystems
Integrated Demo System: Complete system integration showing all subsystems in unified demonstration platform

Day 4: Subsystem Integration

Comprehensive subsystem integration work combining 2D fabrication, 3D printing, PCB milling, and molding/casting to complete all physical components for final assembly and testing.

2.0 Final Electrical Design Upgrades

With the milling machine unavailable, the time was used to upgrade board designs, requiring component rotations and layout optimizations to ensure all components fit properly. As Quentin noted, "you have to get used to rotating it in your head"—a valuable skill for PCB design where spatial reasoning is essential for component placement and routing.

"you have to get used to rotating it in your head" — Quentin

MirrorAge TFT Board Upgrades (v13)

The MirrorAge TFT board design was upgraded to version 13, with component rotations and layout optimizations to improve fit and routing efficiency.

MirrorAge TFT board front side version 13
MirrorAge TFT Front v13: Upgraded front-side layout with optimized component placement and routing
MirrorAge TFT board back side version 13
MirrorAge TFT Back v13: Upgraded back-side routing with improved trace layout and component positioning

Aging Clock TFT Board Upgrades (v16)

The aging clock TFT board design was upgraded to version 16, incorporating component rotations and layout refinements to ensure proper fit within the watch casing constraints.

Aging clock TFT board front side version 16
Aging Clock TFT Front v16: Upgraded front-side design with rotated components for optimal fit
Aging clock TFT board back side version 16
Aging Clock TFT Back v16: Upgraded back-side routing with improved component placement

2.1 2D Fabrication: Laser Cutting and Vinyl Cutting

Laser-cut thinner acrylic (1.35mm) was fabricated to improve the fit of the clear display cover for the aging clock subsystem. The thinner material provides better dimensional tolerance and improved integration with the watch casing.

Laser cutting 1.35mm acrylic for display cover
Thin Acrylic Cutting: Laser cutting 1.35mm acrylic sheet for improved display cover fit
Successfully laser-cut acrylic display cover
Successful Cut: Completed laser-cut acrylic display cover with precise dimensions
Laser-cut acrylic showing edge quality
Edge Quality: Clean laser-cut edges demonstrating precise fabrication
Aging clock with improved acrylic display cover fit
Improved Fit: Thinner acrylic display cover providing better integration with watch casing
Laser Cutting Process: Laser cutting operation for thin acrylic display cover
Final Cut: Completion of laser cutting process for display cover component

2.2 3D Printing: Rigid and Flexible Components

Band clips were printed using TPU (Thermoplastic Polyurethane) material for improved fit and flexibility. The flexible material provides better mechanical compliance and secure attachment to the watch body.

TPU band clips for aging clock watch
TPU Band Clips: Flexible band clips printed from TPU material for improved fit
Aging clock with TPU clips integrated
Integrated Clips: TPU clips providing secure and flexible band attachment
Filed and inserted band clips showing fit
Fitted Clips: Band clips filed and inserted for optimal fit and secure attachment
Complete clip assembly showing integration
Clip Assembly: Complete band clip assembly demonstrating successful integration

2.3 Milling: Single and Double-Sided Boards

The TFT aging clock board design was milled, requiring iterative refinement due to initial design issues. The first mill had traces that were too close together, and the rivets were positioned under the microcontroller, requiring manual fixes with an ultrasonic knife before remilling the corrected board.

First Milling Attempt

The initial milling process revealed design issues that required correction. The board was milled on both front and back sides, with careful tool location and fixturing procedures.

Front-Side Milling: Initial front-side milling operation for aging clock board
Tool Location: Tool location procedure for front-side milling setup
Front Milling Start: Beginning of front-side milling operation
Front Milling Progress: Front-side milling operation in progress
Back-Side Tool Location: Tool location for back-side milling setup
Back Milling Start: Beginning of back-side milling operation
Back Milling Progress: Back-side milling operation continuing
Back Milling Completion: Final stages of back-side milling
Board Unloading: Removing completed board from milling machine
Post-Milling Cleanup: Vacuuming debris after milling operation

Design Issues and Manual Fixes

After milling, inspection revealed traces that were too close together and rivets positioned under the microcontroller. These issues were corrected manually using a two-step cutting process: the ultrasonic knife was used to initiate precise cuts on both ends of each problematic trace, establishing the correct penetration direction. A utility knife was then used to cut a straight line between these initiation points, isolating the upper and lower wiring. The challenge with manual trace cutting lies in controlling the initial penetration with the utility knife—the ultrasonic knife's precision in establishing the cut direction made the subsequent utility knife cut smoother and easier to complete from end to end. After these manual corrections, the board design was updated and remilled with the fixed layout.

Removing milled PCB from machine
PCB Removal: Removing milled board for inspection and testing
First side of milled board showing traces
First Side: Initial side of milled board showing trace routing
Missing traces due to design issues
Missing Traces: Traces that were too close together causing milling issues
Close-up of missing trace issue
Trace Detail: Detailed view of trace spacing issues requiring correction
Additional missing trace locations
Multiple Trace Issues: Additional locations with trace spacing problems
Double-sided board showing both sides
Double-Sided Board: Complete double-sided board showing front and back
Ultrasonic knife for trace cutting
Ultrasonic Knife: Used to initiate precise cuts on both ends of problematic traces, establishing the correct penetration direction for subsequent utility knife cuts. This precision makes the utility knife cut smoother and easier to complete from end to end.
Utility knife for board modifications
Utility Knife: Used to cut a straight line between the ultrasonic knife initiation points, isolating upper and lower wiring. The challenge lies in controlling the initial penetration, which is why the ultrasonic knife's precise initiation cuts are essential.
First trace cut using ultrasonic knife
Trace Cut 1: First trace modification using ultrasonic knife
Completed first trace cut
Completed Cut 1: First trace cut completed successfully
Second trace cut in progress
Trace Cut 2: Second trace modification in progress
Completed second trace cut
Completed Cut 2: Second trace cut completed successfully

Corrected Board Design and Remilling

After manual corrections, the board design was updated to move rivets away from the microcontroller and improve trace spacing. The corrected board was successfully milled with proper trace clearances and component placement.

Corrected aging clock board front side
Corrected Front Side: Updated board design with improved trace spacing
Corrected aging clock board back side
Corrected Back Side: Back side of corrected board showing proper routing
TFT display fitting on corrected board
TFT Fit Test: TFT display properly fitting on corrected board design
TFT display alignment on board
TFT Alignment: TFT display properly aligned with board connectors
Corrected Front Milling 1: Beginning of corrected board front-side milling
Corrected Front Milling 2: Front-side milling operation continuing
Tool Location: Tool location procedure for corrected board milling
Front Milling Start: Beginning corrected front-side milling operation
Tool Change: Tool change during front-side milling operation
Back Milling Setup: Setup for back-side milling of corrected board
Back Milling Start: Beginning back-side milling of corrected board
Back Milling Progress: Back-side milling operation continuing
Post-Milling Cleanup: Vacuuming debris after corrected board milling
Aging clock board with moved rivets
Moved Rivets: Board design with rivets repositioned away from microcontroller
Improved board design with proper rivet placement
Improved Design: Corrected board showing proper rivet placement and trace routing
Rivet holes detail on corrected board
Rivet Holes: Detail view of properly positioned rivet holes

MirrorAge TFT Board Milling

The base amplifier board was remilled after fixing polygon pour isolation settings (changed from 0 to 32 mil). The upgraded MirrorAge board with TFT display was also successfully milled, ready for soldering and testing.

MirrorAge TFT board front side
MirrorAge TFT Front: Front side of MirrorAge board before TFT display integration
MirrorAge TFT board back side
MirrorAge TFT Back: Back side of MirrorAge board before TFT display integration showing routing
Front Milling: Front-side milling of MirrorAge TFT board
Front Milling Progress: Front-side milling operation continuing
Back Milling: Back-side milling of MirrorAge TFT board
Minor trace issue on MirrorAge TFT board
Minor Trace Issue: Small trace spacing issue requiring attention
MirrorAge TFT board front after milling
Milled Front Side: Completed front side of MirrorAge TFT board
Double-sided taping for board fixturing
Fixturing: Double-sided tape used for secure board mounting during milling
Successfully milled MirrorAge TFT board
Successful Milling: MirrorAge TFT board successfully milled and ready for assembly
MirrorAge TFT board back side
Back Side: Back side of successfully milled MirrorAge TFT board
High-quality view of MirrorAge TFT board back
Completed MirrorAge TFT Board: High-quality view of the back side showing proper trace routing and component placement for the TFT-integrated MirrorAge amplifier board.

2.4 Molding and Casting

Starting from Anthony's sketch in the midterm review, 3D-printable open molds were designed to cast watch bands out of MoldStar 30. The process involved printing PLA molds, waxing for release, mixing and pouring the mold material, leveling, curing under a heat lamp, and demolding. The center section of the printed molds required cutting with an ultrasonic knife before pouring to ensure part removability. A backup TPU band was also printed in case of casting failure.

Anthony's midterm review sketch for band mold design
Design Origin: Anthony's midterm review sketch providing the foundation for band mold design
3D printed PLA molds for band casting
Printed Molds: PLA molds 3D printed for watch band casting
Mold A for band casting
Mold A: First half of the two-part mold system
Mold B for band casting
Mold B: Second half of the two-part mold system

Mold Preparation

The molds required cutting out the center section with an ultrasonic knife before waxing and casting. Wax was melted, painted onto the mold surfaces for release, and thinned as needed for proper coverage.

Mold A after cutting and waxing
Mold A Prepared: Mold A after center section removal and wax application
Mold B after cutting and waxing
Mold B Prepared: Mold B after center section removal and wax application
Wax Melting: Melting wax for mold release agent application
Wax Melting Process: Continued wax melting for release agent preparation
Wax Application: Painting wax release agent onto mold surfaces
Wax Thinning: Thinning wax for proper coverage and release properties
Waxed molds ready for casting
Waxed Molds Ready: Both molds properly waxed and prepared for MoldStar 30 casting operation.

Mold Mixing and Pouring

MoldStar 30 was mixed according to specifications, poured into the prepared molds, and leveled to ensure proper distribution and surface quality.

Mixing MoldStar 30 components A and B
Component Mixing: Preparing MoldStar 30 components A and B for mixing
Mixed MoldStar 30 ready for pouring
Mixed Material: MoldStar 30 fully mixed and ready for pouring
Mixing Process: Thoroughly mixing MoldStar 30 components
Stirring: Final stirring of mixed mold material
Pouring: Pouring mixed MoldStar 30 into prepared molds
Molds filled with MoldStar 30
Filled Molds: Molds filled with MoldStar 30 ready for leveling
Leveling: Leveling poured material for even distribution
Leveling Process: Continued leveling to ensure proper surface quality
Leveled molds ready for curing
Leveled Molds: Molds properly leveled and ready for heat lamp curing process.

Curing and Demolding

The filled molds were moved under a heat lamp for curing, then demolded and tested to ensure proper fit between the two band halves.

Molds under heat lamp for curing
Heat Lamp Curing: Molds positioned under heat lamp for MoldStar 30 curing
Curing process in progress
Curing Progress: MoldStar 30 curing under heat lamp
Demolding 1: Beginning the demolding process for cured band
Demolding 2: Continued demolding process
Tab Removal: Removing casting tabs from demolded band
Band Testing: Testing fit between the two cast band halves

2.5 Aging Clock Subsystem Fabrication

The TFT aging clock board was successfully assembled into the watch enclosure, demonstrating successful integration of all fabricated components including the milled PCB, TFT display, and watch casing.

Aging clock board assembled into watch enclosure
Complete Assembly: TFT aging clock board successfully assembled into the watch enclosure, demonstrating proper fit and integration of all subsystem components including the milled PCB, TFT display, watch casing, and acrylic display cover.

Design Files

Comprehensive table of all design files used in the system integration, organized by category with descriptions and links to their usage locations.

File Name Description Category Used In Download
PCB Design Files
agingclock_tft.brd Aging clock watch board with TFT display integration (pulse oximeter, accelerometer, camera) PCB Design Day 2, Day 4 Download
mirrorage.brd Base MirrorAge amplifier board with load cell interface (HX711) and real-time audio amplifier PCB Design Day 2, Day 3 Download
mirrorage_tft.brd MirrorAge amplifier board with TFT display integration (2.4" ILI9341) PCB Design Day 2, Day 3, Day 4 Download
design_xiao.kicad_pcb KiCad PCB design for XIAO ESP32-S3 base board (non-touch version) PCB Design Day 2 Download
design_xiao.kicad_pcb (touch) KiCad PCB design for XIAO ESP32-S3 with touchscreen support PCB Design Day 2 Download
QPAD21.kicad_pcb KiCad PCB design for QPAD21 board (reference design) PCB Design Reference Download
design_micro.kicad_pcb KiCad PCB design for microcontroller board (reference) PCB Design Reference Download
3D Design Files
WatchBody.3mf Main watch body casing for aging clock subsystem 3D Model Day 2, Day 3 Download
Dock.3mf Dock component for board mounting and electrical connection 3D Model Day 2, Day 3 Download
Display Glass.3mf Display cover component for watch face protection 3D Model Day 2 Download
Bands.3mf Watch band components for wearable attachment 3D Model Day 2, Day 3 Download
band-a-scaled.3mf Scaled band component A for casting molds 3D Model Day 4 Download
band-b-scaled.3mf Scaled band component B for casting molds 3D Model Day 4 Download
watchband_clip.3mf Watch band clip component for secure attachment 3D Model Day 3, Day 4 Download
watch v2.5-whole v1.3mf Complete watch assembly model version 2.5 3D Model Day 1 Download
band-a-mold.3mf 3D printable mold A for band casting 3D Model Day 4 Download
band-b-mold.3mf 3D printable mold B for band casting 3D Model Day 4 Download
band-a-mold-print-10p.3mf Optimized mold A print file with 10% infill 3D Model Day 4 Download
band-b-mold-print-10p.3mf Optimized mold B print file with 10% infill 3D Model Day 4 Download
2D Design Files
square_2_final.svg Final laser cutting design for display cover (1.35mm acrylic) 2D Design Day 4 Download
square_2.svg Intermediate laser cutting design iteration 2D Design Day 2 Download
square.svg Initial laser cutting design for display cover 2D Design Day 2 Download
square_2.dxf DXF format for laser cutting (intermediate iteration) 2D Design Day 2 Download
square.dxf DXF format for laser cutting (initial design) 2D Design Day 2 Download
Code Files
blink_ESP32S3.ino Basic blink test code for ESP32-S3 XIAO Arduino Code Testing Download
test_display_ESP32S3.ino TFT display test code for ESP32-S3 XIAO Arduino Code Testing Download
test_touch_ESP32S3.ino Touchscreen test code for ESP32-S3 XIAO Arduino Code Testing Download
test_serial_ESP32S3.ino Serial communication test code for ESP32-S3 XIAO Arduino Code Testing Download
Reference Design Files
design_xiao.step STEP file for XIAO ESP32-S3 mechanical reference 3D Model Reference Download
Seeed Studio XIAO-ESP32-S3-Sense.step STEP file for Seeed Studio XIAO ESP32-S3 Sense board 3D Model Reference Download
TFT LCD 2.4 inch ILI9341 touch.step STEP file for 2.4" ILI9341 TFT display with touch 3D Model Reference Download
SSD1306_OLED_Display(128x64).step STEP file for SSD1306 OLED display reference 3D Model Reference Download
MPU6050.stp STEP file for MPU6050 accelerometer reference 3D Model Reference Download
3006 MAX98357.step STEP file for MAX98357A amplifier reference 3D Model Reference Download
max98357a adafruit.SLDPRT SolidWorks part file for MAX98357A amplifier reference 3D Model Reference Download
apple-watch-se-2nd-gen-band-adapter20251028-1-u4zeat.zip Apple Watch band adapter design files (ZIP archive) 3D Model Reference Download

Critical Path Analysis

Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.

Critical Path Tasks

Phase 1: Design & Documentation MOSTLY COMPLETE
  • CAD model consolidation and system integration design ✓
  • PCB design: combine OLED/accelerometer with pulse oximeter ✓
  • Demo table integration design with subsystem placement ✓
  • PCB design: speaker board with realtime amplifier and TFT (MirrorAge board) ✓
  • PCB design: TFT-integrated aging clock board ✓
  • Band mold design ✓
  • 3D printable cases for board mounting ✓
  • TFT display wiring documentation and integration methods ✓
  • System schematic documentation (wired and wireless)
  • Website documentation updates (Day 1, Day 2, Day 3, Day 4) ✓
Phase 2: Fabrication IN PROGRESS
  • PCB milling: aging clock board milled (with corrections and remilling) ✓
  • PCB milling: MirrorAge board base version (remilled after isolation fix) ✓
  • PCB milling: MirrorAge TFT board ✓
  • PCB milling: TFT-integrated aging clock board (corrected and remilled) ✓
  • Component soldering (boards ready for soldering)
  • Band mold printing and casting ✓
  • 3D printing of board cases (casing, dock, bands, TPU clips) ✓
  • 2D subtractive: laser-cut acrylic display (thinner 1.35mm version) ✓
  • Aging clock subsystem assembly (board, TFT, casing integration) ✓
  • Physical integration: drilling mounting holes, routing power connections
  • Mirror film application to screen
Phase 3: Integration & Programming PENDING
  • Board-level firmware integration
  • WiFi network coordination between boards
  • Server-level code development
  • Serial communication: pulse oximeter to heart display (BPM/SpO2)
  • System wiring and wireless connection setup
Phase 4: Testing & Documentation PENDING
  • Integrated system testing and validation
  • System evaluation and cost documentation
  • One-minute video production (conception, construction, operation)
  • Summary slide preparation
  • Final documentation review and completion

Current Status

✓
Completed:

Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), TFT-integrated aging clock board design, MirrorAge board design (base and TFT versions), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands and clips), laser-cut acrylic display (1.35mm thin version), aging clock board milling (with corrections and remilling), MirrorAge board milling (base and TFT versions), band mold design and casting (MoldStar 30), TFT display wiring documentation with touchscreen integration methods, aging clock subsystem assembly, Day 4 fabrication integration documentation

→
In Progress:

Component soldering (all boards milled and ready), physical integration (mounting holes, power routing), firmware integration, data integration methods documentation (serial, WiFi, MQTT spiral development)

○
Upcoming:

Component soldering, firmware integration, WiFi/MQTT network setup, system wiring, mirror film application, integrated testing, final documentation

Buffer Days (Saturday & Sunday)

Tasks that cannot be completed during scheduled weekdays will be shifted to Saturday and Sunday buffer days. This ensures the critical path remains on schedule while allowing flexibility for unexpected delays or additional refinement work.

Data Integration Methods to Spirally Develop

Progressive development approach for integrating sensor data streams from multiple subsystems, starting with simple serial communication and evolving to wireless network-based architectures.

Method 1: Serial Communication (Easiest)

Direct serial communication through USB cable from computer to microcontroller, using PySerial to stream data. This provides the simplest initial integration path for rapid prototyping and debugging.

Implementation:
  • USB cable connection from computer to ESP32-S3 microcontroller
  • PySerial library for Python-based data streaming
  • Arduino Serial functions for microcontroller-side communication

Method 2: WiFi Client Architecture (Second Easiest)

Configure all microcontrollers as WiFi clients that stream data to a flash web server. This enables wireless communication while maintaining a centralized data aggregation point.

Implementation:
  • All ESP32-S3 boards configured as WiFi clients on the same network
  • Central web server (initially laptop-hosted) receives data streams
  • WiFiClient::write() functions for data transmission

Method 3: MQTT Protocol (Advanced)

Message Queuing Telemetry Transport (MQTT) provides a lightweight, publish-subscribe messaging protocol ideal for IoT device communication. This approach enables decentralized data exchange between all MirrorAge subsystems, allowing each board to publish sensor data and subscribe to relevant topics for coordinated system behavior.

Server Hosting Strategy:

Initial development and testing will use a laptop-hosted MQTT broker. In a later development spiral, the server will be migrated to a dedicated Raspberry Pi Zero or Raspberry Pi 5 for standalone operation and improved system portability. Paho MQTT library has been successfully tested for ESP32-S3 implementation.

Spiral Development Approach

Development will progress through these methods in order of complexity, starting with serial communication for rapid prototyping, then moving to WiFi client architecture for wireless operation, and finally implementing MQTT for advanced decentralized communication. Each subsystem board (pulse oximeter, OLED/accelerometer, speaker/amplifier, load cell) will be integrated progressively, enabling:

  • Incremental complexity management and early validation
  • Decoupled communication between subsystems
  • Real-time data streaming from multiple sensors
  • Scalable architecture for adding new sensor modules
  • Flexible server deployment (laptop → Raspberry Pi migration path)

Reflections & Learnings

Reflections and key learnings from the final project integration week.

Key Points

  • System integration requires careful coordination of mechanical, electrical, and software subsystems
  • Comprehensive planning and day-by-day scheduling are essential for managing complex integration tasks
  • Modular design enables incremental testing and validation of individual components before full system assembly
  • Documentation throughout the integration process supports debugging and future improvements
  • Final integration week demands focus, organization, and the ability to adapt to unexpected challenges

Contributions

Acknowledgments for contributions and collaborations during the final project week.

Ethical AI Use

Documentation of AI-assisted tasks and tools used during the final project integration week.

📋 General Guidelines: See General Commands for Cursor on the homepage for standard guidelines and commands used consistently throughout documentation development.

Cursor · Project Plan & Weekly Schedule

Comprehensive Cursor AI assistance for outlining the project plan and weekly schedule, including documentation structure, content organization, systematic updates across all week pages and the final project page, media integration, and summary generation workflows.

Cursor · Project Integration Updates

Cursor AI assistance for Week 14 project integration updates, including Day 2 electrical and mechanical integration documentation, data integration methods refinement, and critical path analysis updates.

Cursor · Electrical Integration and Fabrication

Cursor AI assistance for Week 14 Day 3 electrical integration and fabrication documentation, including TFT display wiring documentation, board design updates, fabrication integration methods, and Day 3 content updates.

© Saleem A. Al Dajani
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``` Updated both captions with the trace cutting details: 1. **Ultrasonic Knife caption**: Explains it initiates precise cuts on both ends of problematic traces, establishing the correct penetration direction for the utility knife, making the cut smoother and easier to complete. 2. **Utility Knife caption**: Explains it cuts a straight line between the ultrasonic knife initiation points to isolate upper and lower wiring, and notes the challenge of controlling initial penetration, which is why the ultrasonic knife's precise initiation is essential. The captions now reflect the two-step process and how the tools work together. No linting errors were found.