🌱 Propagator

A browser-based control surface for the Spore synthesizer (the Electrosmith Daisy Seed firmware lives in the separate spore repo). Configure Spore's parameters live over USB MIDI - no install, no drivers.

▶ Live: Propagator - open in Chromium based browser with Spore connected over USB.

Run it

Easiest: just open the live site.

To run locally for development - it's a static site, no build step:

# from repo folder
python -m http.server 8000
# then open http://localhost:8000 in Chrome or Edge

Use a Chromium browser (Chrome/Edge). Web MIDI needs a secure context, and localhost counts - so serving over http.server is enough. Safari has no Web MIDI; recent Firefox is partial.

What it does

• Connects to Spore and other MIDI devices, shows live status.
• The 6 hardware knobs + 3 toggles + 2 footswitches, mirrored from the hardware.
• A full Synth voice editor in draggable "pods" oscillator engine (analog / wavetable), tone & voicing, an interactive ADSR graph, LFO 1 / LFO 2, a drag-to-wire patchbay, a piano-roll step sequencer, and a tempo/clock section
• Preset save/load (browser localStorage).
• Firmware flashing in the browser (WebUSB DFU) - the ⤓ dfu button opens a wizard that fetches the latest spore release .bin (or takes a local file), reboots Spore to the bootloader over MIDI (CC 118), and flashes the app to QSPI. An "install / repair bootloader (advanced)" toggle handles first-time setup (CC 119 → STM ROM → internal flash). The write address is auto-derived from the connected bootloader. Chrome/Edge; Windows needs WinUSB once (Zadig).

MIDI map (the contract)

The CC / SysEx map is defined by the firmware and is the single source of truth: see spore/docs/MIDI_PROTOCOL.md. The mirror of it lives in the CONFIG block at the top of app.js (labels, CC numbers, channel) - edit there to extend the surface. Values are 0–127 (0..1 normalized).

Files

index.html    structure + inline SVG filters (boil) and Spore chassis
styles.css    the living blueprint theme + animations
app.js        WebMIDI, pods/knobs/patchbay/sequencer/clock, presets, flash wizard
dfu.js        self-contained WebUSB + DfuSe firmware flasher
presets.json  factory preset library

Contributing

See CONTRIBUTING.md — it's a static site (no build), formatted with Prettier (4-space, 100-col, matching the Spore firmware repo) and enforced by CI. Run npx prettier --write . before committing.

License

GPL-3.0-or-later. Copyright (C) 2026 Joakim Langkilde. See LICENSE. Pairs with the Spore firmware (spore repo), which is GPL-3.0 for the same reason.

AI disclosure

In the interest of transparency: this project was built with substantial help from AI. Code, documentation, and design were generated and iterated with Claude (Claude Code) under human direction and review.