From the MAKE Flickr pool
Routing MIDI data to/from Arduino (or similar) seems like it should be a relatively simple task, but often ends up being much more complex. Mark of Spikenzie Labs created a very handy piece of software for just such occasions. Built using Processing, the Serial – Midi Converter translates makes that basic data stream palatable to common music software –
Normally, to use an Arduino or other micro-controller with your MIDI software you had to build a MIDI-in and MIDI-out circuit with a few parts and an opto-coupler. Easy enough, but then you would typically need a MIDI to USB adaptor to connect it to your computer.
With the SM and a board like you the Arduino with USB, you donâ€™t need any other hardware to get your Arduino to play music with software such as Appleâ€™s GarageBand or Abletonâ€™s Live !
Get the software, source code, and further explanation over at Spikenzie labs.