Known Issues:

• when extension is already connected, sometimes its calibration data doesn't arrive on Connect() and acceleration/orientation values are broken (can be seen in the demo).
  workaround: reconnect extension.
• library doesn't yet handle Bluetooth wiimote disconnection / connection loss.
• Classic Controller data not yet shown in demo app.

Tested:

Ways you can help:

Testing:
- general testing & feedback  (including Bluetooth stack compatibility reports)
- Classic Controller testing  (I don't have one)
- multiple Wiimote testing  (I only have one)

Features:
- how to read the Power button?
- how to Bluetooth (dis)connect from code (maybe via HID API?)  (so it doesn't drain wiimote power after use)

Audio code:
- speaker mute doesn't seem to work?
- ADPCM variant doesn't seem exact  (try Sine wave sample in demo)
and/or
- Occasional glitches (worse with HID writes which seem more jittery) -
    a) are the speaker frequencies exact?
    b) ways to improve output and/or smoothe wiimote sample buffering?
- 'Volume' seems to actually influence decoding in some way  (values other than 0x40 totally warp ADPCM playback).
- is some ADPCM state initialisation required?

Stuff that'd be real handy:
- better wiimote position/orientation estimation.
   (for the basics read this, and for a possible approach read this). ideally should use IR too.

Join my mailing list to get involved.

References:

Wiimote protocols & data:
http://wiibrew.org/index.php?title=Wiimote
http://www.wiili.org/index.php/Wiimote
http://www.auby.no/files/wii/attachment.txt
http://www.wiindows.org/index.php/Talk:Wiimote

Wiimote guts: http://www.sparkfun.com/commerce/present.php?p=Wii-Internals