Seedbox
A generative rhythm and melody machine for a Raspberry Pi Pico 2 W. One 32-bit seed grows a whole tune: a drum part for any sampler or drum machine and a bass, melody and pad line for a poly synth, both over MIDI. Built and tested with a Roland SP-404MKII and an Arturia MiniFreak. You don't program steps. You pick a seed, turn tracks on and off, and steer it with two knobs.
Status: v0.1. The engine and the controls are settled in a browser simulator that drives the real gear over Web MIDI. The stripboard layout has been checked by script and by an independent review. The Pico firmware is not written yet: that's the next step.
What's in the box
| Part | |
|---|---|
| Brain | Raspberry Pi Pico 2 W (RP2350), powered and flashed through its own USB port at the back |
| Screen | Nokia 5110 LCD (PCD8544, 84 × 48) |
| Controls | Encoder with push, ENERGY and DRIFT pots, SEED button, 11 track buttons in a 4 × 3 grid, with the RUN toggle in its top-right corner |
| MIDI | IN (for learning drum pads), OUT KIT (sampler or drum machine), OUT SYNTH. 3.5 mm TRS (Type A), MIDI 1.0 3.3 V spec. |
Repo map
sim/ the browser simulator: index.html, engine.js (portable engine), app.js (UI, Web MIDI)
test/ golden vectors and the scripts that make and check them
hardware/ layout.js (the stripboard, one source of truth) and check-layout.js
tools/ bench pages: wiring.html, bom.html (tick-off parts list), panel.html (panel layout)
docs/ concept, controls, MIDI setup, hardware (BOM, pinout, wiring, panel, SVG drawings)
firmware/ the port plan for the Pico (C, Pico SDK)
Run it
The simulator is a static page. Web MIDI needs a secure context, so serve it over localhost or HTTPS rather than opening the file directly:
npx serve . # or: python3 -m http.server
# open http://localhost:3000/sim/ (Chrome or Edge; Firefox needs a Web MIDI add-on)
GitHub Pages works too: enable Pages for the repo and open /sim/.
Checks (Node 18 or later, no dependencies):
npm test # golden vectors + stripboard netlist
Docs
- Concept: how the music is made
- Controls: the panel, the screen pages, the gestures
- MIDI setup: kit and synth, learn mode
- Hardware: parts, pinout, stripboard, panel
- Firmware plan
- Design decisions
Licence
None chosen yet. Add a LICENSE file before making the repo public (MIT for code and CC BY-SA for the hardware docs is a common pairing).
Credits
The track model leans on Eric Lyon's paper "Techno Counterpoint", an analysis of Aphex Twin's tracking practice. The AMENIZER plays a re-voiced Amen break pattern (The Winstons, "Amen, Brother", 1969).