Projects / FRC hardware / 2026

Driver station button board

A custom PCB for the driver station with 24 lit buttons, built around an ESP32-S3.

I wrote the board's firmware.

C
ESP-IDF
ESP32-S3
TinyUSB
Python

Case study

How it works

Three PCA9535 I2C IO expanders read the buttons and write the button lights
The USB-OTG port (TinyUSB) makes the board appear as a HID gamepad, so the FRC Driver Station reads it as a normal controller

The interesting problem

Sending data from an FRC robot to a HID device is undocumented, so the LEDs could not be driven the normal way.

The solution

A Python program on the driver station laptop connects to the robot over NetworkTables and forwards LED state to the ESP32 as UART commands over a USB-serial link.

Reliability

Automatic serial reconnect if the board is unplugged
A status LED for the USB connection