Quick description :
-A small, cheap (10€ target), PCB with a rgb led(s). Interaction via accelerometer (and maybe capacitive touch).
-Will be used as a way to learn playing with accelerometers
-For now, 3 different applications that I'd like to try :
*The LedyBug : The led behave like the led on a mac (breathing while it sleeps), and react to acceleration (wake up if shaked, turns red if free-falling, ...)
*Electronic dice : you shake it displays random number
*Light painting : change the color with acceleration
Current decisions :
-The MCU might be a pic18fxxK50 : rather cheap for something with USB included, and can do usb without external crystal (saves space and money). Maybe be fast enough to use the pwm for light painting.
Current questions :
-How to power the thing : 150mAh lipo designed for rc planes and a charge controler IC seems to be the best option, but it comes with a cost (3€ at least). Another problem is that swinging around the lipo battery (for light painting) won't be as safe as using coin cells (but 7 rgb leds won't be easy to power with coin cells).
I found a project which is suprisingly close to what I want to do, but does not have onboard leds and is not build around an accelerometer : http://rayshobby.net/?page_id=562#squarewear