Small ESP32-C3 controller board to power two 12V PWM fans from a single USB plug.

Schematic and PCB design can be found in hardware/. It is a KiCAD 6 project.

The schematic is available as a PDF.

The first simple test just loops through {5V/off, 5V/on, 12V/off, 12V/on} with every button press.

Download MicroPython from micropython.org/download/esp32c3-usb/ and flash it with:

esptool.py --chip esp32c3 --port /dev/ttyACM0 erase_flash
esptool.py --chip esp32c3 --port /dev/ttyACM0 --baud 460800 write_flash -z 0x0 esp32c3-*.bin

Then install a virtualenv with adafruit-ampy and upload the main.py:

ampy -p /dev/ttyACM0 put main.py
ampy -p /dev/ttyACM0 reset --hard

The red LED will blink upon every state change.