Guitar Hero Midi Controller

From the time i started playing guitar hero this last Christmas (i know, i’m a little late to the party) I just couldn’t help but think what cool real instrument it would be. I saw the video of the band that uses the PS2 version through usb and knew people were talking to the wii-mote with bluetooth, but i wanted a real instrument, something that was self contained and didnt require a computer to be dragged along in order to make music. So the solution was to make it use midi , then i could use any synth in the world or do whatever i wanted.

With the current version you can:
play 2 octaves of an 8 note scale at a time
change the starting note anywhere in the range of a regular keyboard
change octaves
change keys
change tonal modes (Ionian, Mixolydian, Lydian, Dorian, Aeolian, Phrygian, Locrian)
change the timbre of a sound
change the resonance of a sound
use the whammy bar to pitchbend
play chords in the mode you have the guitar set to (major/minor/etc.)
rock out with a video game toy

First i got the idea together and designed a method of operation. I actually wrote the user’s guide before i did any programming or and hardware slicing. If you check out the USER’S GUIDE page, you can see how all of the control works.

The block diagram of how it works comes next. it goes
Guitar –> Arduino –> LEDs & MIDI –> external MIDI device.

Then the programming and prototyping using todbot’s wiichuck adapters so i didnt have to void the warranty just yet.

once the basics worked it was hardware hacking time. the leds went in (i like leds a bit too much i think). I had the LCD in, but thought it looked too clunky and swapped it out for the status lights. Plus i didnt really need it. Everything that would need to be adjsuted can be done without text feedback.

Then the software was adjusted to do what i wanted it to. The ‘user’s guide’ for the code is below. For the guitar itself GO HERE.

total cost ~
Guitar Hero controller $60
Freeduino $13
various electronic bits $10
wires/cables to cut up $8
plexi $14
time…

in order to make the program run, you’ll need my MIDI library and my guitar library

files needed:
http://www.dwdesignlabs.com/GuitarHeroMidi.zip
http://www.dwdesignlabs.com/midi.zip
http://www.dwdesignlabs.com/guitar_funcs.zip

———————- ————————– —————————–
———————- ————————– —————————–
———————- ————————– —————————–
———————- ————————– —————————–

Finished GHMC

unmodified wii guitar hero controller

test of the chord lights

guts before closing up

MIDI plug

GHMC programming USERS GUIDE

This is a program for Arduino written for the purpose of using a Wii Guitar Hero Controller
as a MIDI input device. As with most arduino projects, this is released under the GNU
understanding. The use of and modification of the software for personal use is granted.
however rights of sale of completed Guitar Hero Midi Controllers, or kits for the same is
reserved. any commercialization of this kit may only be with the express written consent of
the original author.

The use of the MIDI library from https://slapyak.wordpress.com/ is required.
author: Dave Wernli (slapyak)
created: April 2008
website: https://slapyak.wordpress.com/
created in EditPlus (http://wwweditplus.com) multi-language coding text editor
resources:
Midi Guide: http://www.indiana.edu/~emusic/etext/MIDI/chapter3_MIDI.shtml
I2C (wire) library: included with new arduino environment disrtibutions
Wii adaptor/code: Tod Kurt – http://www.todbot.com
Windmeadow labs – http://www.windmeadow.com/node/42
Wii guitar mapping, function basics: Jason Leyrer – http://www.jleyrer.net/
LCD4Bit library: http://www.arduino.cc/playground/Code/LCD4BitLibrary
Arduino Playground: Serial, test library, countless tidbits from the forum posts

The end user user’s guide can be found at https://slapyak.wordpress.com/
this is more of a programming guide to the software and hardware involved

Notes:
——————————————————————————–

Hardware: everything is made so no hardware modification is necessary to the
guitar hero controller. though i did cut up mine a little, with some modification
you could use the software without needing to cut anything up.

I’ve commented the code pretty excessively and tried to compartmentalize as much
as possible. This is partially for my benfit while writing the thing, and
partially for anyone who would want to use this.

general notes:
midi standard usually uses Hexadecimal (0x00) notation, so thats
what i’ve used here. You are free to use standard decimal everywhere though.

The Wii guitar hero controller connects to arduino via I2C protocol. and is accessed
with the Wire library. Wire and LCD4Bit funtions called with wire.* and lcd.* are
covered very well in the documentation for their respective libraries.

Below are the functions and an explanation of how they are used in my program.

PROGRAM FUNCTIONS:
————————————————

GUITAR DATA RECIEVE AND PROCESS FUNCITONS:
————————————————
GENERAL NOTE ABOUT HOW I GET THE DATA.
I wanted to be absolutely sure I didnt miss a strum and therefore notes. So, I
linked the strumbar to an interrupt via an optoisolator. I’m working on a software solution
that assures me of not missing any notes, but it isnt 100% yet.

Guitar.init();
returns nothing
run in the setup function to initialize the communication with the wii guitar.
can also be run as a reset to re-establish a link if drop out is possible.

Guitar.refresh();
returns nothing
gets new status data for access.
NOTE: this function must be called to get new data, otherwise you are just calling
the same data over and over. I did this because there are times in my program i want to
set a state, get the status of everything in that state and access it repeatedly.
you can always just build this funtion into another to avoid calling it a thousand times.

Guitar.strumUp();
returns byte
returns 1 for up strum

Guitar.strumDn();
returns byte
returns 1 for up strum

Guitar.whammy();
returns byte
returns value, 0-255 for posistion of whammy bar
0 is off, 255 is full down.

Guitar.joyX();
returns byte
returns x position as -127 to +127

Guitar.joyY();
returns byte
returns y position as -127 to +127

Guitar.buttons();
returns pseudo array of buttons as binary byte
it makes sense to see it.
Bud0abcde –
where u is 0 or 1 based on down strum state
where d is 0 or 1 based on up strum state
where a is 0 or 1 based on Yellow button state
where b is 0 or 1 based on Green button state
where c is 0 or 1 based on Blue button state
where d is 0 or 1 based on Red button state
where e is 0 or 1 based on Orange button state
returned value would be B01011111 when you strum up with all 5 buttons down
the B before the number is just letting the program know its in binary notation just
like 0x signifies a hex notated number.

These next functions return 0 or 1 as a byte for button states. 1 means the button is pressed…
Guitar.yellow_but();
Guitar.green_but();
Guitar.blue_but();
Guitar.red_but();
Guitar.orange_but();
Guitar.plus();
Guitar.minus();

MIDI FUNCTIONS AND THEIR PARAMETERS:
————————————————
(required) (optional) (optional)
Midi.noteOn(byte _note, byte _velocity, byte _channel);
EXAMPLE CALLS:
Midi.noteOn(0x3C); plays middle C at full(127) velocity(default) on channel 0(default)
Midi.noteOn(0x3C, 0x64) plays middle C at 100 velocity on channel 0(default)
Midi.noteOn(0x3C, 0x64, 0x0A) plays middle C at 100 velocity on channel ten
_note: the note to be played 60 is middle C, 61 is a half-step up, etc…
accepts decimal(0-127) or hexadecimal(0x00 – 0x7F)
will automatically bring a note above 0x7F down an octave until it
is a valid note.
_velocity(optional): optional parameter, but must be included if channel is included
if left out, 127 will be default.
accepts decimal(0-127) or hexadecimal(0x00 – 0x7F)
_channel(optional): an optional parameter, if left off, all notes go to channel 0

(required) (optional)
Midi.noteOff(byte _note, byte _channel);
EXAMPLE CALLS:
Midi.noteOff(0x3C); turns off playing note, middle C on channel 0 (default)
Midi.noteOff(0x3C, 0x0A); turns off playing note, middle C on channel ten
_note: see above
_channel: see above

(required) (optional)
Midi.pitchBend(int _bend, byte _direction);
EXAMPLE CALLS:
Midi.pitchBend(0x3F01, 1);
_bend: a number between 0 & 16129 (127*127) due to its 2 byte length.
_direction: defaults to 1, which would indicate up (0==down)

Midi.pitchReset();
resets pitch bend to 0 and plays whole tones. (normal operation)

Midi.omniOn();
turns omni on. This allows a message sent to any channel to be played on all channels
It could be used to perform, but helps with debugging when you are using
multiple channels at a time. For detail about Omni, Mono, Poly and other modes,
consult the Midi guide referenced above.

Midi.omniOff();
see Midi.omniOn()

Midi.modePoly(byte _chan);
sets polyphonic mode on. This means you can have more than one note playing at a time.
modes must be either mono or poly.

Midi.modeMono(byte _chan);
sets monophonic mode on. This means only one note per channel will be played at a time.

Midi.sustain(bool _status);
sets sustain pedal to on for _status==1 and off for _status==0

Midi.volume(bool _level);
accepts _level val from 0-127 for overall volume control

Midi.porta(bool _status);
accepts _status as 0 or non-zero for on/off control of portamento

Midi.suste(bool _status);
accepts _status as 0 or non-zero for on/off control of sustenuto