Play the Classics on This Laser Harp
If you’re more Electric Daisy and less Ren Faire, then you can build this compact laser harp and start plucking.
A harp is one of those instruments that feels unattainable. Where do you even buy one? Do they sell them at Guitar Center? Actually, they do. But we live in the future and stringed harps are for Renaissance-era Spaniards anyway. If you’re more Electric Daisy and less Ren Faire, then you can build this compact laser harp and start plucking.
This instrument has the familiar harp shape and six “strings.” Except there aren’t any physical strings. Where they would be, there is just empty space. But if you wave your hand in that area, you’ll hear a note and see a red laser dot on your hand. The red lasers (5mw diodes) are only there for visual feedback and the harp senses your hand using Adafruit infrared break beam sensors.
A Raspberry Pi Pico 2 W development board monitors those sensors. When your hand breaks the infrared beam, the board plays the corresponding note through an Adafruit DAC (Digital-to-Analog Converter) and Adafruit amplifier. The Pico 2’s RP2350 microcontroller generates that note using the synthio library for CircuitPython.
The harp’s body is an easily assembled stack of laser-cut plywood sheets. It should be easy for anyone to put together and will weigh a lot less than a “real” harp. Because there are no strings under tension, this Laser Harp’s body doesn’t need to be particularly strong and is therefore inexpensive to build.