Firmware for the Useless Box V3
More information: https://y-fablab.ch/uselessbox/
PCB: https://github.com/y-fablab/u3-pcb
Schematics: https://github.com/y-fablab/u3-pcb/blob/master/doc/schematics.pdf
Sound files: https://github.com/y-fablab/u3-sound