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Raspberry Pi Pico Project Automatically Tunes Any Guitar String

Raspberry Pi
(Image credit: Guyrandy Jean-Gilles)

Music is notably mathematical, so it should come as no surprise that many makers turn to creating their own Raspberry Pi-based solutions for musical problems. Today we’ve got a sharp, problem-solving creation to share from maker Guyrandy Jean-Gilles. Tired of twisting his pegs, Jean-Gilles opted to develop his own Raspberry Pi Pico-powered automatic guitar tuner.

The project design is inspired by the Roadie 3 automatic tuner from Band Industries. However, Jean-Gilles’s creation is housed inside a custom, 3D-printed shell and is built from scratch for a more affordable end product.

Jean-Gilles was kind enough to release the project as open-source for anyone interested in recreating it. He provided a full parts list of everything you need to get started, aside from the 3D printer and filament for the housing. The tuner is built on top of a Raspberry Pi Pico. To turn the pegs, it uses a GM11a DC motor. An Electret Microphone (Jean-Gilles specifies with MAX4466 adjustable gain) is used to listen to the string as it’s tuned. You’ll also need a button, 8-way rotary swing, an L293D Dual H-Bridge, some LEDs, and an Adafruit Powerboost 1000c module.

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Raspberry Pi

(Image credit: Guyrandy Jean-Gilles)
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Raspberry Pi

(Image credit: Guyrandy Jean-Gilles)
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Raspberry Pi

(Image credit: Guyrandy Jean-Gilles)

Users place the tuner directly on the tuning peg for the string they wish to tune. Holding the button down on the tuner will activate the microphone. When the string is plucked, the tuner will automatically rotate the peg until it determines the tone from the string is in tune and trigger the LEDs to flash green.

We often say the best Raspberry Pi projects are the ones you can make at home, and this is definitely one of those projects. To get a closer look at how this Pico-powered automatic guitar tuner works, visit the official project page at GitLab. There you’ll find all of the source code as well as 3D printer files for printing the shell.