http://austindavid.com/t/wiiceiver-github

The Wiiceiver is a drop-in "plug and play" replacement for a
standard R/C receiver.  It has a Nintendo Wii Nunchuck 
connection, a 3-pin ESC connector, and an available connector
for an external BEC if required.  

The Wiiceiver is intended for use on an electric skateboard.
The Y-axis (up/down) is throttle -- push up to speed up,
middle is neutral, down is brakes.  These function roughly
the same as on a standard RC transmitter.

Wiiceiver also implements a few additional functions:
- X/Y joystick axes, X/Y/Z accelerometers, and the two buttons 
  are monitored to confirm that the nunchuck is "active" -- 
  as opposed to dropped or low battery.  When "inactive" the
  wiiceiver returns to neutral, and will not re-start until 
  it detects and active neutral signal
- C button is "cruise control" -- press and hold C to maintain
  the current throttle level.  Drop the joystick to neutral to
  cruise.  While holding C, pressing the joystick "up" will
  increase speed gently, "down" will decrease speed.  
  Releasing C returns to neutral.
- Control smoothing: Wiiceiver implemenets an exponential 
  algorithm to smooth the controller input.  As currently
  tuned, an instant 0-100% throttle input will result in a
  gradual change to the ESC over the course of about 1s.

It has been tested to work with a corded Nintendo nunchuck, a 
Memorex wireless nunchuck, and a Nyko Kama wireless nunchuck.