Code to turn an arduino into a usb joypad for an aracde machine. To control the lights, see IgniparousTempest/rpi-arcade-lights.
Verify that the Arduino is configured correctly using jstest:
$ justest /dev/input/js0
I soft "bricked" my fake Pro Micros a few times while uploading code to them, to unbrick them, we can simply burn the Arduino Leonardo boot loader to them using an Arduino Uno as an ISP, see (here)[https://eldontronics.wordpress.com/2019/06/16/arduino-pro-micro-clone-port-not-detected/].