Homemade Pikocores, ports, and alternate firmware

Infinite Digits

More from the shop

Builds by Ground Grown Circuits, bellabebop, Electrical_Lake9586, and Faux Cyrillic. Images used with permission.

Back to the shop

One of my favorite parts of making the Pikocore open-source has been seeing what people do with it. I made it as a very small sample mangler with eight buttons and four knobs. Other people apparently looked at that and thought it needed arcade buttons, a screen, a keyboard, a Eurorack panel, or a completely different circuit board.

I started collecting these versions because many of them were scattered across Instagram posts, Reddit threads, YouTube videos, and GitHub repositories. Some have complete build files and some have only a short video. They are all interesting to me because they show how much the physical interface changes the way the same firmware feels.

Here are fifteen homemade Pikocores, ports, and related projects I could trace back to their makers.

starting with the schematic

The Pikocore source code, schematic, bill of materials, and DIY walkthrough are available online. That is enough information to build one, though it still leaves a lot of decisions for the builder.

The original Pikocore is intentionally cramped. I wanted something that could fit in a pocket and run from one AAA battery. If you make your own, there is no reason to keep those restrictions. You can spread out the buttons, use parts you already own, or make the whole thing enormous.

Most of the builds below started with exactly that decision.

arcade buttons

Ground Grown Circuits / Noah Jolly built one of the first large Pikocores I saw in July 2023. Noah replaced the small tactile switches with eight illuminated arcade buttons and put everything into a handmade case. It looks like something you are supposed to hit instead of cautiously press with one finger, which suits the Pikocore pretty well.

There was one useful note from the build. The LEDs in the arcade buttons could use some buffering to make them brighter. This is the sort of small problem that only becomes obvious once you take a circuit designed for tiny LEDs and connect it to something much larger.

Ground Grown Circuits / Noah Jolly. View the original source.

2ononen made another arcade version in a compact blue case. It has glowing green buttons, four knobs, and toggle switches across the top. The case is still small enough to carry around, but the buttons have enough room that you can play it with more than one finger at a time. A lot of the comments on the original post were simply people asking where they could get the enclosure.

2ononen. View the original source.

Mid-Air went much bigger. Their Pikocore, documented by the 100% BOOTLEG channel, has four knobs and eight arcade buttons on a broad black panel. The build video includes construction photographs and also shows how to send a synchronization pulse from a DAW into the Pikocore.

Mid-Air / 100% BOOTLEG. View the original source.

All three use nearly the same controls, but they feel like different instruments. The small blue box is portable. The Ground Grown Circuits version looks like a little arcade machine. The Mid-Air version gives both hands room to work.

building the circuit by hand

Andr DIY Music built a Pikocore around an RP2040 clone and added an ATTiny85 audio spectrum display. It ended up in a colorful brick enclosure with the tiny display moving along with the music. Andr published a short build video, a full 95-minute construction stream, the wiring, and a link to the ATTiny85 spectrum project.

I like that this build adds something completely unnecessary. The display does not make the sampler sound better, but it makes the machine more fun to watch and gives the finished object its own personality.

Andr DIY Music. View the original source.

Reddit user bellabebop made the hand-built “Another 7×9” Pikocore on a large green board. It uses a 16 MB RP2040, four knobs, discrete LEDs, and two rows of four switches. The maker originally tried arranging all eight switches in one row, but found that two rows made simultaneous presses much easier.

The build thread has several practical details. Bellabebop recommended RK097 pots for a finished build and less expensive RV09 trimmers while breadboarding. They also spent several days tracking down a problem with simultaneous button presses, which is a good warning to test the combinations and not only each button by itself.

bellabebop. View the original source.

The “Break F**ker Upper” started on a breadboard, moved to perfboard, and finally got a custom orange 3D-printed enclosure. Reddit user Electrical_Lake9586 used a Pimoroni Pico LiPo, added debounce capacitors and a flyback diode around the sync transistor, and printed the case, button holder, and buttons for the project. The extra parts cost about £15 because most of the material was already sitting around the workshop.

Electrical_Lake9586. View the...