The 12 is the number of steps per octave, and the 60 is the base MIDI note number. The lit up button means that it is in monophonic mode, which basically means it will retrigger the last note when necessary. Pushing the button toggles the light off and sets it in 16-voice polyphonic mode and does not retrigger the last note. More details about retriggering are to come when I post about the code.
Here you can see inside a little better without flash, but the LEDs wash out. The parts list is below. I used some LEGO bricks to wedge the main boards in place.
Another angle shows the MIDI out port. The MIDI in port is on the left side. I turned the encoder knobs to set it to 10 steps per octave and 62 as the base MIDI note number. I hope to post video soon to show it in action.
Here is a parts list:
- Sparkfun Redboard
- Arduino protoshield
- Hammond project box
- 2 x MIDI ports
- illuminated push button
- 2x Bourns rotary encoders
- 2x knobs
- 4-digit seven segment display, common anode
- 6N138 optocoupler
- resistors: 1x 10K, 8x 220
- 100 pF capacitor
- 1N914 diode
- headers to connect the protoshield to the Redboard
- 2x 6 pin sockets to for the display
- 8 pin socket for the optocoupler
- male-to-female cables cut in half used for encoder pins and the Arduino RX pin
- some wire