SolarOS 4.13.4 manual · job

midi

Bidirectional MIDI transport on an exclusive named MIDI bus. The bus selects an available UART controller internally; users supply only its MIDI name, TX and RX pins, and an optional baud rate.

expansion bus create midi midi0 tx=gpio1 rx=gpio2
job start midi midi0
job status midi
midi status
job stop midi

The default rate is the MIDI DIN rate of 31250 baud. Incoming channel voice, system-common, and realtime messages are decoded with running-status support and published to subscribers such as the Synth app. Outgoing messages are queued with midi note-on, midi note-off, midi cc, midi program, or midi send. Status reports RX and TX byte/message counts, unsupported parser input, queue drops, and the last transport error.

Run midi monitor and move a controller to identify its mapping. The monitor prints CC: <channel> <controller> <value> for control changes and KEY: <channel> <note> <velocity> for note activity. Note releases use velocity zero. The app-exit key, Esc, or q returns to the shell.

Up to 16 exact incoming MIDI CC addresses can also be registered as scalar streams. This lets the controls job map a MIDI controller through the standard normalized control path to any live application parameter:

midi stream add 1 74
control create cutoff midi.cc.1.74 0 127
control bind cutoff parameter synth.filter.cutoff pickup=off
job start controls
synth

Use midi stream list, midi stream remove <channel> <controller>, and midi stream clear to inspect or remove the volatile definitions. A stream is waiting until the running MIDI job receives its first matching value.

Use a compliant electrical interface: MIDI IN requires an optoisolated receiver and MIDI OUT requires a current-limited driver. Do not connect DIN MIDI pins directly to ESP32 GPIOs.