Hi there! I made a 32 note range (that's 2 2/3rds of an octave folks!) GH/RB mod!
It shares a common ground and power source with the controller's chip, then intercepts the button presses before reaching said chip. It's piggybacking, really. Since you're not cutting anything up,
(1) It stays backwards compatible with the original game (in theory, obviously I can't test EVERY model out there!)
(2) It works with all versions of the GH/RB controllers!
so far, there's support for:
- Hammer-ons
- Whammy bar
- Decrease/increase your base octave with start/select (or your controller's equivalent)
- press start+select to toggle chord mode, strumming up/down for minor/major chords
and planned support for:
- the secondary frets of those RB guitars (I just need a toggle pin to sense when the other set is being pressed)
- an acoustic mode, involving bitbashing to generate square waves with a user defined duty cycle.
If you want to give the code a look, my github page's at: https://github.com/superquinn/arduino-hero
My (relatively) super in-depth guide on the whole thing's at: [Arduino] MIDI Guitar Hero full build+play guide (32 note range) (Page 1) - Tutorials, Mods & How-To's - Forums - ChipMusic.org
(I consider that page my home base!)
Oh, and I'm a chiptune fan, so the default octave range is the same as that of a gameboy! (easily changed in the defines)
And yes, it's called Arduino-Hero. What else SHOULD I call it?
(actually Guitar-Duino rhymes pretty well... I'll put a tab on that one...)