SPOKE: The RP2040 Touch Controller That Plays Music From Fruit
Cheap microcontrollers have quietly turned music-making into a hardware hobby. Boards built around the RP2040 now sit at the center of homemade synths, MIDI pads, and touch instruments that would have cost hundreds a decade ago. The SPOKE fits right into that wave: a CD-sized board covered in capacitive touch pads that plays a note the moment you brush a finger across it. What the SPOKE actually…
The RP2040 Touch Controller, aptly named SPOKE, is a compact board adorned with capacitive touch pads, designed to produce music upon the slightest brush of a finger. Sporting a 27 copper touch pad layout each linked to a GPIO pin on an onboard RP2040 chip, the SPOKE operates as a standard MIDI controller when linked to a computer via USB-C.
Upon visiting spokeboard.com, enabling MIDI access through the browser triggers notes on each pad. The platform further enriches the user experience with audio visualizers, a Harmonic Table, a one-shot drum kit, and an Audio Playground, where users can import audio clips from Freesound.org or their own recordings.
Programming the SPOKE is as straightforward as editing code in Thonny or the browser-based Code Playground over serial, as the firmware runs CircuitPython - mirroring the programming experience of a Raspberry Pi Pico. By default, the pads are set to a pentatonic scale, five notes per octave, but users can modify this by adjusting note values within the default program.
Two Qwiic / STEMMA QT ports afford the option to integrate additional sensors, though this action will disable a few pads. Individual NeoPixels on each pad shift color upon activation. It's worth noting that pressing the Reset button recalibrates touch sensitivity each time a new component is integrated.
The SPOKE transcends mere music-making. It encourages users to extend the pads with any conductive material, turning a bowl of fruit into a makeshift drum kit. From there, users can incorporate arpeggiators or step sequencers from the code examples, or remap the scale to suit their own musical compositions. Alternatively, building a similar setup from scratch using a Raspberry Pi Pico, a few copper pads, and CircuitPython's touchio library is entirely feasible.
For further exploration and all play modes, the original write-up is available on raspberrypi.com.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written; read the original for the full account.
