i have constructed a wireless sensor system for my performance costume. it has 2 accelerometers (3-axis adxl330, sparkfun - same as in the wii remote i believe) and 4 switches (digital). both master and slave uses a microcontroller (atmega8, atmel) and a transceiver (mirf v2, sparkfun).
below is a short video, some pictures, supercollider classes and also the schematics and the complete firmware if you want to build the thing yourself.
the avr programmer (usbtinyisp kit v2.0) and the electronic parts needed...
the master and slave...
sensors sewn in...
081008 update: slave firmware and slave schematics updated - added 2 more switches (pd6 and pd7)
081010 update: also attached the supercollider class RedUniform.sc with helpfile
trying to finish this custom controller before leaving for japan. almost ready now - just the casing left to do. it has 5 rotary encoders (endless) with as many push buttons, 2 softpots and 3 touch sensors (capacitive). it is built using the absolutely brilliant avr-usb from obdev and shows up like a standard HID devices. small, lightweight and just one cable (usb). plus it is very cheap to build - see parts list. the biggest cost is the encoders.
i took some inspiration for the design from kenton's nice but expensive killamix mini, but wanted a few different types of controllers and also have them arranged asymmetrically. this so i don't have to look at the device while playing. when i've tried other controllers with evenly spaced knobs, i've often lost track and have had to look down and even start counting knobs to figure out which one i was using. with this layout i won't have this problem. also the layout resembles the shape of my upcoming performance costume redUniform.
schematics, partslist and firmware attached (v1.0). a proper release is here.
this is my hacked front light for my bike. it's a tiny45 avr microcontroller that i programmed to play the complete 14min drum part in ravel's bolero. the reason i picked bolero was that it's a fairly well known rhythm and that it's very repetitive (= don't require much memory).