The OpenChord.org 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.
|the OpenChord.org real guitar controller|
(still from the intro video)
(photos from the build instructions)
|The frets can be connected with wire...|
|...or with conductive tape.|
|wired, conductive-tipped pick|
an example of how the scanning matrix works|
(diagram adapted from the manual)
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.
The manual describes how to use the controller in more detail.
Like a keyboard matrix, the OpenChord.org guitar controller is susceptible to ghosting: some fret inputs are electrically identical, so the controller can't tell them apart.
|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.
OpenChord.org Open-source real guitar controllers
The main page of the OpenChord.org 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 OpenChord.org controller.
Keyboard Matrix Help - ghosting and masking
An explanation of keyboard matrix ghosting and masking.
OpenChord.org Buy page
The OpenChord.org purchase page.
The developer's blog post that explains the project is on hiatus.