[Andy] came across this guitar midi controller project from way back and decided to send us a tip about it. The English version, translated from the original Russian, is easy to follow and documents the build process from first prototypes to the version you see above. It can connect via a standard MIDI cable and then be used to control anything you want. The only thing missing is the ability to transmit velocity data, but that’s certainly not a deal breaker.
The device has two sensory parts. The first is a set of pickups that can be seen underneath the strings near the bridge. These work like standard magnetic pickups but instead of extrapolating fret data from the pitch picked up on the string, there is a second sensor mechanism for every fret of each string. Since the strings are made of metal, it’s possible to detect which fret is depressed based on continuity sensing. Of course this means you need a conductor between every fret, and that’s why the fingerboard has been replaced with one made of printed circuit boards. All of this data is gathered, then sent to the MIDI device via a PIC 16F74 microcontroller.
If this leaves you wanting for more guitar hacks, don’t miss this one that adds addressable LEDs in between each fret.