I have a Seeeduino XIAO and it works well so far apart from trying to use MIDI. I am using the Adafruit_TinyUSB.h library and for basic note on / note off stuff it works fine. However, as soon as I send a CC message ( in my case CC 7 - volume ) strange things happen. Messages don’t appear to be sent until another note on message. So I will send a note off message followed by a CC message and nothing appears in the midi monitor. So the note is hanging. As soon as the next note on message comes along out pops the note off and the CC message followed by the note on message.
If you take the midi-test from the libraries’ example folder and change the step through time to one second, then replace the send section with:-
// Send Note On for current position at full velocity (127) on channel 1.
MIDI.sendNoteOn(note_sequence[position], 127, 1);
MIDI.sendControlChange(7, 100, 1) ;
MIDI.sendNoteOff(note_sequence[position], 0, 1);
// Increment position
You will here the notes hanging until replaced by the next one. If you comment out the sending of the CC message, it works as expected with just a short beep for each note.
Problem is it is not an Adafruit product so I don’t think they would be interested. So has anyone any suggestions?