This project is based on https://www.instructables.com/Arduino-Soundlab/ from rgco (Rolf Oldeman).
Its a 2 operator fm synthesizer running on a arduino nano.
license: https://creativecommons.org/licenses/by-nc-sa/2.5/
Because the arduino is not capable of usb host mode without extra hardware I use a serial to midi conversion tool called ttymidi: https://github.com/cjbarnes18/ttymidi This tool emulates midi over usb serial connection with the arduino. You can use it as a midi device on your pc via usb and control it with standard midi controllers.
This command should be enough to make the arduino visible as a midi device:
ttymidi -b 9600 -s /dev/ttyUSB0
You can connect the arduino to another midi program by:
aconnect -i # list available MIDI input clients
aconnect -o # list available MIDI output clients
aconnect 128:0 129:0 # where 128 and 129 are the client numbers for
Or use a graphical tool for the connection like qjackctl.
The arduino should respond to all midi notes played by all channels and should respond to the first 8 controlchanges by all channels.