The circuit for this Arduino based guitar looper is fairly simple. Keep in mind the Arduino is only one small part of this build. The guts of this project is a patch for Pure Data which does all the audio crunching. via Arduino.cc

Here’s how to make a little pedal for electric guitar. The idea is to connect the Arduino pedals, and using software to control sound processing, we made ourselves with Pure Data. Here I show you an example of a looper, but it can also be a rack of effects without problem.

In the Maker Shed:
Makershedsmall
Arduino Family
Make: Arduino