This instructable will show you how to take a regular electric guitar and turn it into the OpenChord V0, a Guitar Hero / Rock Band controller that you play by actually playing notes on the guitar. Instead of pressing buttons, you'll be pressing strings, sliding up and down the fretboard to connect notes together. However, it still relies on the internals of a Guitar Hero controller to generate the proper signals to the console, and it uses the strum bar from the controller as well.
This project has been superseded by the OpenChord V1, which actually uses the real strings and generates real controller signals.
For a little more information about the project as a whole, visit OpenChord.org.
Step 1: Theory of Operation
Why almost? Once more than one string is involved, some ambiguous situations arise. For instance, electrically, holding two strings down at the second fret is no different from holding one finger down on the first fret and another on the second fret, because the fret connects everything together. Fortunately, we'll deal with this in software...