After putting a piezo-neopixel circuit inside drums, juggling balls seemed like a natural next step. With 3D printed juggling balls and some electronics from Adafruit (most notably the 5V Trinket and more Neopixels) the circuit was soldered up and smashed into a translucent plastic ball.
I used “transparent” ABS plastic from Hatchbox to print off a model juggling ball that screws together. After some basic acetone vapor smoothing the end result was decent. There is a lot more that will be done with this in the future, securing the electronics inside the ball, replacing the piezo with an accelerometer, making a custom PCB etc.. But for a proof-of-concept its functional and fun.
3D Model: http://www.thingiverse.com/thing:290450
Much more polished version by someone else: http://jonathanjamieson.com/2014/04/25/smart-balls/
See it in action
See the insides!
In hindsight some thruhole neopixels and stranded wire would have done wonders, but the end result would still be a reactive juggling ball. On to rev 2!