For my personal project I wanted to make a dj scratch table using max and Arduino. The idea was to have a series of buttons, a couple potentiometers, and a motor. The box containing all of these pieces was laser cut from acrylic and the disk was also cut form acrylic. The motor was attached to the the red disk and the idea was that it would track which way it was turning and I would use max to apply a scratching effect based on that. The buttons would control different samples and the potentiometers would control things like EQ and reverb. However when I hooked up the ardunio to max, I could not get any stable readings from the motor. It would bounce around randomly and did not give any reliable data. What I learned upon further research was that an encoder attached to the motor would do exactly what I wanted. It tracks the rotational motion of the the motor so it would tell me how far it spun.
So I ignored the motor and just used the potentiometer and buttons. In the end the final design had 3 buttons and 1 potentiometer. Now came what I thought was the easy part. I spent hours google methods of applying scratch effects with max and finally gave up and found methods to do it with ableton. I settled on the this method https://www.youtube.com/watch?v=HH3ryAEP308. From there my scratch table essentially became a midi controller which I accomplished by sending note values with noteout in max whenever I pressed a button. I got the max patch and ardunio code from http://playground.arduino.cc/Interfacing/MaxMSP and then modified it to suit my needs.
However getting the dial in max to control a value in ableton was very difficult. I ended using multimap after running around trying to find access to the software (which is why my project is so late).
Then there came the issue of getting the buttons and potentiometer to work together also the tutorial I watched was in a different version of ableton so it made it hard to handle. But I finally managed to produce a semi scratchie sound shown in the video above. A problem I noticed while scratching was I couldn’t turn the potentiometer fast enough so it lacked the punch of a usual scratch sound.