This add-on expects a configuration file to live at /config/midimonster/midimonster.cfg See: https://midimonster.net/getStarted.html#creating-a-new-configuration
(This config should be moved to the config tab in HA)
To access a USB MIDI controller, it need to run privileged, so disable "Protection mode".
[backend midi]
name = HomeAssistant
detect = on
[backend mqtt]
[midi esx]
read = ESI MIDIMATE eX:1
write = ESI MIDIMATE eX:0
epn-tx = short
[mqtt homeassistant]
host = mqtt://addon_core_mosquitto
user = addons
password = mypass
clientid = midimonster-hass
protocol = 5
[map]
homeassistant.midi2mqtt/midi_out/channel/{0..15}/note/{0..127} > esx.ch{0..15}.note{0..127}
esx.ch{0..15}.note{0..127} > homeassistant.midi2mqtt/midi_in/channel/{0..15}/note/{0..127}