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
Theme of the Week
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
- 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
- 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
- Milling boards
- Print mold and cast band
- Print cases
- Solder components on milled boards
- Connect boards with wired (and wireless connection codes)
- Mirror on screen (easy way with the film)
- Document fabrication
Friday
- Board level codes
- Server level codes
- Document codes
- Finish anything else
Saturday
- Demo integrated system
- Test integrated system
- 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
- 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
- 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
- Moving base of mirror
- Raspberry Pi Zero (or server host, do some research)
- 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.
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.
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.
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:
- 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)
Print Failures and Iteration
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.
2.2 Electrical Integration
Electrical design integration now combines the accelerometer/camera board with the pulse oximeter board into a single unified design that fits inside the casing. The integrated board may be upgraded to include a small TFT screen in a future iteration if space constraints allow.
Board Design Evolution
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.
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
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.
1.8" TFT LCD: ST7735 controller, 128×160 pixels. CAD model reference: GrabCAD ST7735 Model
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.
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.
Critical Path Analysis
Project management view of the integration schedule, showing task dependencies, critical milestones, and current progress status.
Critical Path Tasks
- 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)
- Band mold design
- 3D printable cases for board mounting ✓
- System schematic documentation (wired and wireless)
- Website documentation updates (Day 1 & Day 2) ✓
- PCB milling: aging clock board milled (fit optimization in progress)
- PCB milling: MirrorAge board (pending design completion)
- Component soldering (pending board fit resolution)
- Band mold printing and casting
- 3D printing of board cases (casing, dock, bands) ✓
- 2D subtractive: laser-cut acrylic display ✓
- Mirror film application to screen
- 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
- 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
Subsystem testing and validation, CAD model consolidation, demo table integration design, aging clock PCB design (accelerometer/camera + pulse oximeter), 3D printing of mechanical components (casing with organic support, dock with brim, TPU bands), laser-cut acrylic display, initial board milling
Board fit optimization (casing adjustment vs. miniaturized board), MirrorAge board design (handgrip + speaker + TFT), data integration methods documentation (serial, WiFi, MQTT spiral development)
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.
- 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.
- 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.
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.
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.
