Cheap stuff gets our creative juices flowing. Case in point? [Andy Grove] built an eight-sensor HC-SR04 breakout board, because the ultrasonic distance sensors in question are so affordable that a … ...

Using a Raspberry Pi mini PC together with inexpensive HC-SR04 ultrasonic sensors as inputs, the system generates MIDI notes which can be played through a synthesizer on the Pi to output high ...

It uses a Raspberry Pi and an HC-SR04 ultrasonic sensor to monitor the water level in a sump pit, log the readings and send SMS e-mail alerts if the water rises above a predefined level.

With the processing power available from the Pi, the modernized instrument is able to output MIDI as well which makes this instrument easily able to interface with programs like GarageBand or any ...