littleBits i20 sound trigger

My son claps once and the whole circuit lights up, which is exactly the reaction I was hoping for. The threshold dial takes a little fiddling to ignore background noise, but once it's set it triggers reliably.

Wired this between a power Bit and a bright LED, and now my kid just yells at the circuit to switch the light on. The threshold dial takes a little fiddling to find the right room noise level, but once it's set it reacts fast.