Finally a good attempt to make an Arduino Based controller. Steve Cooley is presenting his Beatseqr.
The data is sent to the computer via OSC. Source code for the project is available on github.
Comment & congratulate on Beatseqr blog for the time and effort.
via [MAKE]
from MAKE:
When we last covered recotana’s Open Sound Controller (OSC) library for Arduino (ardOSC), he had an Arduino talking to an iPhone using the OSC protocol. The project worked quite well, however you had to manually connect the two together by specifying their IP address. Now, by adding an implementation of Bonjour, the Arduino can link up to the iPhone automagically, allowing one to easily get on with their mixing.
Arduinian Tales 