Im trying to reprogramm the 8u2 as generic MIDI device. I got as far as sending hard-coded MIDI-messages to my computer, but i cant catch the serial messages sent from my Arduino and change them to MIDI-messages.
As base file i took the Arduino-usbserial.c
I think my fault lies in taking the wrong variable as input from the atmega:
I had MIDI working in the other direction (computer to arduino) but that was easier. Even then it only seemed to work on Linux and not on Windows so I gave up.
Getting MIDI from the Arduino into the computer is a little harder. From reading the docs I think you have to wait for all the bytes of the message to come through before sending it (usually 3 bytes). So you do have to do a little parsing of the data as it comes in. Don't bother with ringbuffers, you don't need them at MIDI speeds, just send each complete message as you get it.
I might have another look at it again in the future, i have an idea for a project which might need it...
I got it to work now, after i decided to throw out all this ringbuffer stuff since i found a very simple command to read serial messages from the arduino on this forum (Serial_IsCharReceived() and Serial_RxByte()).
The parsing i do on the function channelMidiMessage, i save the messages in an array of length 3 and as soon as i have 3 messages i put it together and send it further on.
If anyone is interested, my colleague will put the project on sourceforge as soon as were finished with it and i will post the link here
Thx for the help