Bavi_H's Blog

Real guitar controller mod

by Bavi_H, 8/14/2010

The guitar controller starts with a real electric guitar, then adds wiring to the metal strings, wiring or conductive tape to the metal frets, and a wired, conductive-tipped pick to create a scanning matrix. All the wires lead to a circuit board that converts the fret and pick inputs into appropriate fret and strum controls for Guitar Hero, Rock Band, or Frets on Fire. The controller can connect to a USB cable or a Wii Remote for use with a PC, Wii, or PlayStation 3.

[ guitar controller]
the real guitar controller
(still from the intro video)
[wired strings]
wired strings
(photos from the build instructions)
[wired fret]
The frets can be connected with wire...
[taped fret] [copper tape traces] [tape meets kit]
...or with conductive tape.
[wired pick]
wired, conductive-tipped pick
[scanning matrix example]
an example of how the scanning matrix works
(diagram adapted from the manual)

Basic use

Guitar Hero strum bar

Touching the pick to any string corresponds to pressing the Guitar Hero strum bar. In menus, touching the pick to one of the three strings closest to the ground corresponds to a down strum; touching the pick to one of the three strings furthest from the ground corresponds to an up strum.

Guitar Hero fret buttons

The manual describes how to use the controller in more detail.


Like a keyboard matrix, the guitar controller is susceptible to ghosting: some fret inputs are electrically identical, so the controller can't tell them apart.

[ghosting example] [ghosting example]
ghosting examples from the manual


The controller is currently available in kit form. The developer plans to sell guitars with the controller pre-installed in the future, and accepts pre-order deposits. But due to low interest, the project is on hiatus while the developer works on other projects.

Links Open-source real guitar controllers
The main page of the website.

OpenChord V1 Building Instructions
The building instructions pages, with pictures and descriptions of the building process.

OpenChord V1 Guitar Manual (13 April 2010) [PDF]
The latest PDF manual for the controller.

Keyboard Matrix Help - ghosting and masking
An explanation of keyboard matrix ghosting and masking. Buy page
The purchase page.

The developer's blog post that explains the project is on hiatus.