Some Raspberry Pi projects are so unique you just have throw out the “Why?” and replace it with “Why not?” to fully appreciate them. Today’s project is very much in that spirit, and was created by maker and developer Guy Dupont. Using a board powered by our favorite microprocessor, the RP2040, he’s managed to create an effects pedal, not for an electric guitar, but for keyboard and mouse input.
To use the pedal, your keyboard and mouse must be plugged directly into the effects pedal, which connects to your computer using USB. The pedal accepts input from the keyboard and mouse, then processes the output to your computer with custom effects. Are these effects practical? Hardly. But they’re hilarious and you might find a use case for them anyway!
We won’t give away all the features, but here are a few to give you an idea of what it’s capable of. The mouse can be set to ‘Reverb’ which will push the cursor continuously in one direction when you stop moving. The ‘Looper’ effect lets you record mouse input so it can be replayed on loop. Using ‘Tremolo’ on the keyboard will adjust the “volume” of your input by periodically applying the shift key. One of our favorite effects is the ‘Crossover’ mode which turns your keyboard into a mouse and mouse into a keyboard.
To bring the project together, Dupont created a custom PCB that connects the main processor to all of the components. It’s driven by a SEEED Studio Xiao RP2040 and connects to things like a potentiometer, an SPDT toggle switch, a knob cap and a footswitch. A parts list is available at Digikey for anyone curious about everything that goes into its assembly.
Dupont was kind enough to make the project open source, so anyone is free to explore the source code. According to Dupont, the firmware is C/C++ based and uses the Raspberry Pi Pico SDK. It also uses the Pico PIO USB library for added USB support.
To get a closer look at this Raspberry Pi project in action, check out the demo video shared to YouTube and look through the project’s GitHub page for greater detail.
