Stateful MMC Play/Stop button

[mungewell]

I see that each button can be configure to send various things, including (either) MMC Start and MMC Stop.
https://github.com/shanteacontrols/OpenDeck/wiki/SysEx-Configuration#message-type

I would like to have a single button foot-switch to supplement my pedal board.

Is it possible to have a 'stateful' MMC button, ie first press sends 'Start' and second press sends 'Stop'... for ever as button is repeatably pressed?

If not possible in settings; is it possible to fake with additional wiring. Such that multiple button inputs and LED outputs are used to create the 'state memory'.

[mungewell]

Maybe (ab)using presets?
https://github.com/shanteacontrols/OpenDeck/wiki/Presets

[mungewell]

Yes. Presets lets you (easily) do this... I wired a single momentary switch to both BUT0 and BUT1 on a Pico.

Preset 1:
BUT0 = MMC Play
BUT1 = Switch to Preset 2 (val=1)

Preset 2:
BUT0 = MMC Stop
BUT1 = Switch to Preset 1 (val=0)

OpenDeckUI-Backup-2025-11-06-00-47.sysex.zip

The only quirk I saw was that when the preset changed I got a load of note outputs. Buttons are configured to notes by default and their state is sent on a preset change, so I changed all the other buttons to mode 'None' to prevent this.