Here is, a HOW-TO about how to break beams of laser light to trigger the sounds, instead of keys.
The cardboard laser piano is based on Arduino UNO, with photosensitive modules, laser emitting diodes, JQ6500 voice module combined, the simple electronic piano detects high-low level current outputted by the adjustable photosensitive modules via laser radiation, thereby sending different orders which represent different notes to JQ6500 module. Users can replace notes and songs anytime, only they’ve downloaded the pre-recorded audio into JQ6500 module in advance.
The simple electronic piano can be easily ported to Raspberry Pi and other open source platforms. It’s easy to operate and convenient to DIY.