Vijay Rajkumar

How To Make (almost) Anything Fall 2021

Weekly Progress

  • about
    1. Computer-Aided Design
    2. Computer Controlled Cutting
    3. Electronics Production
    4. 3D Scanning and Printing
    5. Electronics Design
    6. Computer-Controlled Machining
    7. Embedded Programming
    8. Molding and Casting
    9. Input Devices
    10. Output Devices
    11. Networking and Communications
    12. Interface and Application Programming
    13. Final Project

    Week 9: Output Devices

    LED Array

    I knew for the final project, I'd likely want to integrate an LED array

    In class, Neil had mentioned charliplexing as a way to make a LED array while reducing the number of pins required out of the microcontroller and number of resistors.

    I watched a few tutorials online and looked at projects from previous years to get a sense for how to design one of these boards.

    Here is my KiCAD Schematic.
    kicad

    Pretty much all of the examples I saw from previous used the ATTiny 44 instead of a SAMD. I wasn't entirely sure why, but also remembered Neil saying that this board was outdated. I held off on doing this till I had a better understanding of what I was doing. I also thought cutting a board out of copper vinyl rather than milling th board on a copper plate so that I could have a larger array without the need of jumper wires.

    Eventually I needed to make an LED array and was in a bit of a time crunch to get things working. In case I didn't end up having time to mill and solder all of my LEDs I went to MicroCenter and purchased a NeoPixel 8x8 LED array. This way I could make sure all of my software was working and practice programming the LED arrays.

    Eventually I needed to make an LED array and was in a bit of a time crunch to get things working. In case I didn't end up having time to mill and solder all of my LEDs I went to MicroCenter and purchased a NeoPixel 8x8 LED array. This way I could make sure all of my software was working and practice programming the LED arrays.


    kicad

    I didn't yet have my new ESP 32s which I had ordered, so I hooked the LED matrix to an arudino uno board I had.

    Following some examples I found online, I began programming my own animations. You can find the code here (based on the example files I followed).


    red

    blue

    When my esp arrived, I soldered the connections to my board. This wasn't so inuitive because at first the wires would not solder onto the board pins. I realized I just needed to increase the temperature of the soldering iron to get it to work.


    esp connection

    To my relief, the ESP 32 worked with the same code!


    esp works