Arduino/ATMega MIDI to CV code for hardware module
I used Larry McGovern's repo for the basis of this with a couple of differences:
- MCP4922 rather than MCP4822 (essentially 10bit vs 12bit resolution).
- 6N137 rather than SFH618 opto-coupler which is faster.
- Bare bones ATMega168 (with bootloader) rather than Arduino mini.
- Omitted pitch bend and control change.
- Added changeable clock pulse interval (24 ppq, 12 ppq and 6 ppq), hence 16th, 8th and quarter note pulses.
- Added MIDI channel DIP switch (4bit) so channel 1-15 selectable or omni-mode.
- Added tuning pot to the note CV output rather than using series resistors, allows finer tuning to the 1v / octave.
- TL072 rather than LM324N op-amps as I had a load of TL072 and TL074's.
- Added FTDI programmer header to allow updates to the software to be easily uploaded.
- Added clock reset gate to handle stop / start MIDI events.
- Add parts list
- Schematic