OpenTheremin V3 - MIDI Input under Sonic Pi v3.2.1

Support, Help & Resources
1
Hardware & Software Details

Hardware:
OpenTheremin V3

Firmware:
OpenTheremin_V3 With MIDI

Software:
Hairless MIDISerial Bridge
loopMIDI Virtual MIDI Loopback
Sonic Pi v3.2.1 x64 PAF

Issue Summary:
Got my OpenTheremin V3 hooked up to SonicPi! Works great using a slight tweak to the MIDI example code in the documentation, but I don’t know how to take advantage of the the pitch_bend and control_change messages it fires, just the note_on as per the example.

# Welcome to Sonic Pi
live_loop :midi_OpenThereminV3 do
  use_real_time
  note, velocity = sync "/midi:loopmidi_port:0:1/note_on"
  synth :tb303, note: note
end

Furthermore, the volume antenna does not seem to function at all to control the volume of the midi signal as I would expect.

Here’s where I stand currently:

Just stepping up and down through the pitch scale. Volume was moved a few times to no effect. Last message logged was the “pause” button on the OpenThereminV3.

2

You are not actually using the velocity information at all in your code.
You should try something like

# Welcome to Sonic Pi
live_loop :midi_OpenThereminV3 do
  use_real_time
  note, velocity = sync "/midi:loopmidi_port:0:1/note_on"
  synth :tb303, note: note,amp: velocity/127.0
end

velocity will be a number in the range 0-127 By dividing it by 127.0 you will get a number in the range 0.0->1.0 which you can use to control the amplitude of the note.
(You divide by 127.0 and not 127 to get floating point division, not integer division)

2 Likes
3

Excellent, thanks so much for your assistance!

I’ll try that later tonight and see if it behaves as expected.

4

Hm, does not seem to operate as intended.

Working with the author of the MIDI firmware for the OpenTheremin to see what I’m doing wrong.

Thanks!