Wiimote/Extension Controllers/Guitar Hero World Tour (Wii) Drums

Note: This is different from Rock Band drums, which are USB.

The Drums are identified by the 6 bytes: 01 00 A4 20 01 03 at register address 0x(4)a400fa. The first 01 indicates that it is drums and not a guitar (which would be 00). To read these bytes unencrypted, you must first write 0x55 to 0x(4)a400f0, then 0 to 0x(4)a400fb. Trying to read the 6 bytes after initialising the old way will just return FF FF FF FF FF FF, like many other expansions.

Data Format

The drum kit reports its information as 6 bytes of data, readable at 0x(4)a40008 and streamable using Data Reporting Modes that include Extension bytes. The Guitar Hero World Tour game uses mode 0x37 with continuous reporting. The data is packed into the six bytes as follows (after decryption):

	Bit
Byte	7	6	5	4	3	2	1	0
0	0	0	SX
1	0	0	SY
2	MIDI Note							Velocity<3>
3	Velocity<6:4>			Channel				Velocity<2>
4	Velocity<1>	1	1	B-	1	B+	1	Velocity<0>
5	O	R	Y	G	B	Bass	1	1

R, B, and G are the drum pads by colour (Red, Blue, and Green). O and Y are the cymbals. Bass is the pedal. B- and B+ are the black - and + buttons behind the Wii Remote. They will be 0 when hit, 1 when not.

SX and SY are the black analog stick behind the Wii Remote. 0x20 means centered.

The data from the drum kit is based on the MIDI standards. All the data is inverted, so you will need to invert the data the bytes before it will make any sense. The MIDI note and velocity data are 7-bit numbers, and the MIDI channel is a 4-bit number. Note that you will need to add 1 to the MIDI channel, as the MIDI standard starts at channel 1, but the value from the kit starts at 0.

Since the data is inverted, bytes 2 and 3 will be FF FF if there is no data present.

If a MIDI device is plugged into the MIDI port, than any notes are passed directly through. The following notes and channel are used for the built-in pads:

Name	MIDI Channel	MIDI Note	Standard Midi Value	Raw Value
Kick Pedal	10	C2	36	0x5B
Red	10	D2	38	0x59
Green	10	A2	45	0x52
Yellow	10	A#2	46	0x51
Blue	10	C3	48	0x4F
Orange	10	C#3	49	0x4E
Hi-hat pedal	10	E7	100	0x1B

Note that unfortunately the MIDI message type is not sent to the console, so it isn't possible to differentiate different message types when they are sent via the MIDI in port.

For the hi-hat pedal (unmarked 3.5mm jack above bass pedal jack), the velocity varies according to how far the pedal is pressed. The pedal to connect to the jack is not the same as the bass drum pedal; it must be a some sort of variable resistor (varying between 20k Ohms when down and 40 Ohms when up seems to give a good spread of velocity values). The drums seem to only send a value when they detect you pressing the pedal, and once you do then the pedal will send its changing value for a few seconds. This means if you are testing with a variable resistor, you will only see a velocity when turning it in one direction but not the other. This jack is compatible with pedals from Rock Band drum kits however, and there was a talk by the developers stating that this was the original function for this unused jack. Note that RB pedals are digital, so you will only ever see a velocity of 127.

Thanks to Metallica1969, death_au, l0stsign, MonkeyJamboree, sanjay900 and Carl Kenner.

Sensitivity adjustment

The sensitivity of the pads, cymbals and pedal can be adjusted via MIDI Control Change messages sent to the MIDI IN jack. Activision released a "Drum Tuning Kit" program for this purpose.

The first byte is always 0xBF (Control Change message on channel 16).

The second byte determines which sensitivity to adjust: 0x68 for red, 0x69 for yellow, 0x66 for blue, 0x6A for orange, 0x67 for green, and 0x64 for the pedal.

The third byte determines the sensitivity, with lower values representing higher sensitivities. Activision's software offers 21 different sensitivity levels, which are then scaled to this byte as follows:

Sensitivity level = 0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 20
Byte (Pads)       = 28 1E 19 16 14 13 12 11 10 0F 0E 0D 0C 0B 0A 09 08 07 06 05 04
Byte (Cymbals)    = 3C 35 2E 29 26 22 1E 1B 18 16 14 12 0F 0D 0B 09 08 07 06 05 04
Byte (Pedal)      = 33 2D 28 24 21 1E 1C 1A 18 16 14 12 10 0E 0C 0A 09 08 07 06 05

Sensitivity adjustments will reset once powered off unless manually saved. To do this, the software sends 0xBF6503, waits 750ms, then sends 0xBF7777.