Scarp is a platform for building musical toys that need buttons :) It uses a Raspberry Pi Pico as a processor.

scarp with pocketoperator

Kits can be purchased for 50 Euros and fully assembled for 86 Euros. See below for a depiction of the BOM :)

I was frustrated with my pocket operators and got some inspiration from picokore. Because I’d like to swap things in the design I decided to make a slightly bigger thing where you can actually get at all the pins. Also, I decided to make a design where you can swap the use of the SDA/SCL pins between a DAC and a display. I also wanted to add a way to move the grooves when chaining with Pocketoperators without the hassle. With scarp, it’s a few simple movements to modify the groove while your playing live.

Open Sources includes several versions as fritzing files, and a folder of different firmware.

scarp production

The scarp project, named like it’s brethren, rampart and keep (aka. moat) is an experimental, open hardware design. It takes a page from todbot (circuitpython guru guy) and infinitedigits (nyblycore and pikocore) designs to make a hybrid that’s more easily extended or adapted.

Scarp can include a 4pin I2C display. Or a 4 pin I2S DAC. All the pins on the pico are exposed and you can add headers to use them. The kit and builds include an oled.

The kit also includes a 1.3 inch disply, 8 buttons, 8 leds, 2 pots and an encoder.

scarp pcb


It features an 18650 battery holder :) I hate swapping batteries on the PO series. The battery on scarp will get you through a semester :) Important is the flexibility for modding. It has space for modifications.

The kit contents can be seen here:

scarp kit contente


There’s a bunch of firmware experiments to build on:

The firmware directory includes a number of types of firmware. You’ll be able to do work with the bare pico sdk, circuitpython, or arduino. firmwares

Include examples for

The Pikobeatbox Drum sequencer started with, derived from for the the Pikocore. Then it got out of control. I created scarp to make a beatbox with a euclidean sequencer that’s easy to tweak quickly.

This project was inspired by Teenage Engineering, pikocore designed by Zack Scholl, the todbot circuit python audio stuff and his layouts for a simple sequencer.

It’s a lot of fun to work on.