Changes

= Extension Controllers =

= Extension Controllers =

The Wii Remote includes a 6-pin proprietary expansion connector, which carries synchronous serial data to and from external add-ons, using a two-wire interface. Currently, Nintendo has released the Nunchuk and the Classic Controller, the Guitar Hero guitar is also available as an extension. These addons map onto a portion of the Wii Remote's register space, and can also stream data out through Output Reports (see [[#Data Reporting | Data Reporting]] for a list of modes which include Extension Controller data).

The Wii Remote includes a 6-pin proprietary expansion connector, which carries synchronous serial data to and from external add-ons, using a two-wire interface. These include the Nunchuk and the Classic Controller, the Guitar Hero guitars, the Guitar Hero World Tour drum kit, and Wii Motion Plus. These addons map onto a portion of the Wii Remote's register space, and can also stream data out through Output Reports (see [[#Data Reporting | Data Reporting]] for a list of modes which include Extension Controller data).

== Registers / Initialization ==

== Registers / Initialization ==

{{BoxCenter|'''Reminder'''<br />Remember to set bit 2 (0x04) on the first byte of the Output Reports to write to registers!}}

{{BoxCenter|'''Reminder'''<br />Remember to set bit 2 (0x04) on the first byte of the Output Reports to write to registers!}}

Extension Controllers are mapped at register address 0xa40000. The data is 0x100 bytes long, and it is mirrored across the entire 16-bit address space up to 0xa4FFFF. These registers are readable and writable. Communications are optionally encrypted, and explicit initialization is required to disable encryption (see below).

 

Other extension Controllers are mapped at register address 0xa40000. The data is 0x100 bytes long, and it is mirrored across the entire 16-bit address space up to 0xa4FFFF. These registers are readable and writable. Communications are optionally encrypted, and explicit initialization is required to disable encryption (see below).

In encrypted mode, bytes can be decrypted using the following transformation:

In encrypted mode, bytes can be decrypted using the following transformation:

===The Old Way===

===The Old Way===

The old way to initialize the extension was by writing 0x00 to 0x(4)A40040, but that only works on Nintendo's own brand extensions and the GH3 Guitar, and will fail on 3rd party wireless nunchuks and GHWT extensions. If it fails, the 6 bytes will be FFFF FFFF FFFF. With this method you must decrypt the extension bytes to read them.

The old way to initialize the extension was by writing the single encryption byte 0x00 to 0x(4)A40040, but that only works on Nintendo's own brand extensions and the GH3 Guitar, and will fail on 3rd party wireless nunchuks and GHWT extensions. If it fails, the 6 bytes will be FFFF FFFF FFFF. With this method you must decrypt the extension bytes to read them.

===The New Way===

===The New Way===

===Encryption setup===

===Encryption setup===

After the identification is read, the encryption can be set up if required. This is done by enabling encryption by writing 0xAA to extension register 0xF0, and then writing the 16-byte key to register 0x40. The key is written in 3 blocks of 6, 6, and 4 bytes. After this the extension can be operated in full encryption mode.

After the identification is read, the encryption can be set up if required. This is done by enabling encryption by writing 0xAA to extension register 0xF0, and then writing the 16-byte key to register 0x40. The key is written in 3 blocks of 6, 6, and 4 bytes. (Writing a single encryption byte to register 0x40 will work on genuine Nintendo controllers, but not on others). After this the extension can be operated in full encryption mode.

== Extension Controller Documentation ==

== Extension Controller Documentation ==