Embedded Lab

Tyler Bletsch’s Nickelphone is a coin-based music keyboard that has 15 nickels and 10 pennies arranged on a traditional 25-key piano-style layout and act as touch sensors. It can emit simple square wave tones through an onboard piezo buzzer, but its primary use is as a MIDI keyboard, so it can drive a full synthesizer (like FL Studio on PC). Tyler used an ATmega644 microcontroller for his project so that he would have enough I/O pins (each key uses its own I/O pin) for the 25 keys.