09.07.2010

CV-lovers out there - Have a looksee @ the new version of the 1VpOct sketch for Arduino/MidiVox, aptly named - MidiVox_1VpO_v2.zip (details @ top of .pde file)

Hrrm … fairly certain some higher MIDI notes are somehow gating the CV signal which would effect a notes release in resulting synth output. Will squash this asap.

Otherwise, connections are same as previous, V-trig & S-Trig type Gate signals available from Arduino pins 5 & 4 respectively. Control Voltage signal available from pin 8 of the MCP4921 DAC chip (additionally, remember to disconnect nearby resistor from that pin) - and don’t forget to connect grounds between your synth and MidiVox/Arduino.

To put that in a more “step-by-step” context:

How To: Use a MidiVox shield as a MIDI->CV converter.

1. Disconnect the 909Ω resistor from pin 8 of the MCP4921 DAC chip.
2. Solder a wire to to pin 8 of the MCP4921
3. Determine if your synthesizer uses V-trigger or S-trigger type Gate standard. Solder a wire to pin 5 if you're using V-trigger, or pin 4 if you're using S-trigger.
4. Solder a wire to one of the "GND" ground pads on the MIDIVOX shield
5. Connect the CV, Gate, and Ground wires to the appropriate jacks or solder points on your synth. Connect a MIDI device to the DIN-5 jack on the MIDIVOX shield
6. Upload the 1-Volt-per-Octave CV sketch to your Arduino.
7. Synth it up, Synthia!