I made a controller that uses an ADXL 335 Accelerometer and an Arduino board that communicates serially with Max MSP. The Max MSP patch is a simple sequencer that allows users to choose any audio file to be assigned to 6 different tracks.

The x-axis of the Arduino controller affects the speed that the sequencer is played and the y-axis affects the intensity of a delay affect which is enabled with digital pin push buttons.

The controller has inputs for 5 tracks, and the 6th button applies the delay affect on all tracks. Here are links to the Max MSP code (plus the abstraction) and the Arduino code. The buttons are connected to Digital Pins 2 through 6, and LEDs can be connected to Digital Pins 9 through 13. The acceleromter X axis is connected to Analog Pin 0, and the Y axis is connected to Analog Pin 1.

A special thanks to Daniel Jolliffe for the code that provides Analog and Digital communication between the Arduino and Max MSP.

I plan on doing further iterations and updates to the MaxMSP code as well as the controller in the near future, and I'll be sure to post an update when I have that together. You can see full details on the project here.