DIY Mpr121 Itsybitsy32u4 Capicitive Midi Instrument USB MIDI touch instrument adapted from Bareconductive code (https://github.com/BareConductive/touch-usb-midi-interface) for Adafruit IstyBitsy32u4 and Adafruit Mpr121 (use with Arduino hardware cores https://github.com/rkistner/arcore)