[Noisebridge-discuss] How do I get midi messages from Arduino into a MIDI program, like Traktor?

[Michael Shiloh]

Although I'm pretty comfortable with Arduino, I'm not very plugged in to 
the MIDI music control scene, although I understand the underlying 
technology.

Note that the word MIDI here refers only to the protocol. There is no 
MIDI plug: it's MIDI over USB.

One of my students wants to build a MIDI input device for Traktor, which 
is a music manipulation program. The MIDI input is not a keyboard or 
other musical instrument, but rather a generic set of knobs and sliders 
that can be mapped to certain Traktor functions.

I suspect this same mechanism is used by a wide range of music and other 
programs, so that arbitrary control surfaces can be used to control 
various functionality. (I think I've heard of a video editor working the 
same way.)

My student, Trevor, wants to use Arduino to build his control surface.

I can handle the Arduino/sensor/USB side of things, but I'm mystified as
to how to make it appear as a MIDI input to Traktor.

Trevor showed me how you add new inputs (controllers) to Traktor, and
there is a pulldown menu for manufacturer and model.

I guess that when you buy an off-the-shelf MIDI control surface, it 
comes with a driver that makes it appear to be a MIDI device, which the 
application software can then attach to.

These means that for any DIY device like Arduino, we must provide the 
equivalent of this driver, that speaks the right protocol and convinces 
applications like Traktor that it is a legitimate MIDI device.

I'm sure that this software exists, and that it's free, but I have no
idea what it's called, or where to find it, or, if I can write it, what 
I should make it do.

Any advice?