TouchwheelSAO

Capacitive touchweel SAO for Hackaday Supercon 2024

Features

• Three capacitive touch pads arranged in interleaved disk, builds on touchwheel0
• Three "Neopixel"-compatible side-light RGB LEDs that shine through the center
• Standard SAO pinout w/ I2C. Spare GPIO lines wired to UART TX/RX
• Finger position 0-255 readable via I2C, LEDs controllable via I2C. See register map for details
• One status LED on back of board
• ATtiny816-based, same as seesaw boards
• Easy compilation using standard Ardiuno toolchain and megaTinyCore
• Uses modified TouchyTouch captouch library, included

Production details

• View BOM
• View SCH PDF
• Production files: gerbers zip, bom csv, positions csv

Renders:

Production version (cat approved):

https://github.com/user-attachments/assets/31f27016-510a-4a7b-9d95-70a69f371cc3

Prototype Demo:

https://github.com/user-attachments/assets/b0e4c4f9-f228-49bc-8d6e-ceb53a960fb6

Prototype Renders

• Render2:

https://github.com/user-attachments/assets/08d6583a-afa1-4c01-aba5-ca108eea4f24

• Render1:

https://github.com/user-attachments/assets/c628ba94-1a07-43ad-b761-b3852f8f35f7

Notes:

• Related to touchwheel0
• Uses ATtiny816, using megaTinyCore for Arduino
• 9Sep2024: Originally designed for QFN, but SOIC requested. ATtiny816 comes in hilariously wide SOIC
• 16Sep2024: Back to QFN for ATtiny816 for JLC assembly.
• 16Sep2024: SAO header must be hand switched to be same side ("top") as SMD in positions.csv for JLC to assemble it correctly