We've all wanted it. Now you can build it.
Instant dance parties.
Personal theme music.
Motion activated music.
Step 1: Gather Electronics
Wave Shield - Adafruit
Arduino Uno - Adafruit
SD Card - Adafruit
ADXL335 Accelerometer - Sparkfun
Female Headers - Sparkfun
Toggle Switch - Jameco
9V Battery Snap - Jameco
9V Battery - Adafruit
X-Mini Speaker (surprisingly good sound quality for the size) - Amazon
Web Belt - Most workwear clothing stores
Soldering iron & solder
3D printer for the case
Step 2: Solder & Test the Wave Shield
In order to program the wave shield you'll need to download the WaveHC library and put it in the libraries folder within the Arduino program files.
Audio files need to be converted into 22KHz, 16-bit, mono .wav files. If you don't know how to do this, follow this tutorial using either iTunes or Audacity.
My experience with the Wave shield is that it can be fickle. I highly recommend loading a formatted song onto the SD card and testing out this shield with this example. This example should automatically search for any properly formated wave files on the SD card and play the songs all the way through. If it doesn't start playing, check the serial monitor to see what error messages you are getting. If a song starts playing, you are good to go!