[Wilfred's] brother outfitted a snare drum with LEDs for Dutch Carnival. They faded through different colors randomly and were a nice addition to the normal looking instrument, but [Wilfred] suggested that the LEDs change color with each drum stroke. He set out to design a controller circuit to provide the functionality and ended with a small package based around an ATtiny2313 microcontroller. A piezo buzzer is used to detect the vibrations inside the drum, each hit triggering a different color combination. The LEDs fade to off after each impact as if dying along with the sound, and when not struck for 30 seconds the system defaults to a red heartbeat pattern. See for yourself after the break.
We’d love to see this feature added to each drum in one of those robotic drumsets.