this was a personal project utilising the official Tangible Waves diy kit. i wanted to build a simple module capable of receiving 4 channels of midi over bluetooth, and outputting 4x gates and 4x cv.
i discovered theTinyS3mcu and realised it had the required capabilities in a very small form factor.
to get accurate cv i paired it with this i2c quad DAC from adafruit: https://learn.adafruit.com/adafruit-mcp4728-i2c-quad-dac
and to raise the gate voltages from 3.3v to 5v i just about squeezed in thisquad level-shifter.
the ultimate goal was to send multiple channels of midi from software such as the fantasticorca by hundredrabbitsand also the multitude of interesting ipad sequencers out there.
further details and arduino code on github: https://github.com/fauxcyrillic/BTLE-MIDI-2-CV