Haunted FM-1

Five generative firmwares for the M-VAVE FM-1 pocket synth, each built around one idea, all of them after the kind of haunted ambient music Burial makes: pitched-down ghost vocals, vinyl crackle and rain, sub bass under detuned pads, swung off-grid percussion, long stretches where almost nothing happens, and arrangements that leave and come back changed.

Firmware	The idea	SELECT is	ALGORITHM is
MIDNIGHT ROUTE	The song has a shape before it has notes: a route of 16 stations with a density envelope per part	your position on the route	the route's shape
VOICEMAIL	A voice that almost says something: formant vocal fragments, chopped, stuttered, reversed, in a call-and-answer	pitch, with the formants held	who is singing
UNTRUE STEP	Garage with no grid: every hit is a time in milliseconds with a spread, and the drums leave and come back changed	shuffle, from push to swing	the groove
HALF-LIGHT	Harmony as weather: chords move by voice leading every few seconds under a pressure that builds and breaks	the pressure	the climate
WORN TAPE	A loop you play once; every pass wears it out and grows something new in the holes	the tape's age, both ways	the medium

The designs, with every control, are in docs/DESIGN.md. Each firmware has a manual in its docs/MANUAL.md.

Install

The flasher page (GitHub Pages, built by the workflow from main): open it in Chrome or Edge with the FM-1 on USB, pick a firmware, press Install. The page also puts M-VAVE's stock firmware back. Any of the five installs over any other.

From the command line: pip3 install mido python-rtmidi, then

python3 base/tools/fm1_install.py worntape-0.1.fwsc

Installing firmware is at your own risk. An FM-1 that fails to start twice comes up in a safe mode the installer can reach; one that does not start at all is recovered with felucca-bsp's rescue tool.

Build

Everything is built on fm1-base (base/, a git submodule, with felucca-bsp inside it). Clone with --recursive.

sh tools/get_toolchain.sh          # JieLi's clang for the pi32v2, into ~/.jieli/toolchain
sh tools/get_sdk.sh                # the three JieLi SDK files the package needs, into ~/.jieli/ac79-sdk
pip3 install Pillow                # the fonts are rasterised at build time (PYTHON=... picks the interpreter that has it)
sh tools/build.sh worn-tape        # firmware/worn-tape/build/worntape.fwsc (Docker on macOS: the toolchain is Linux x86-64)
sh tools/build.sh worn-tape --host # the host simulator, then:
sh tools/test.sh worn-tape         # its scenarios (firmware/worn-tape/tests/*.txt), screenshots and audio in build/scenarios/
sh tools/build.sh worn-tape --web  # the browser emulator (needs Emscripten)

The names are the directories under firmware/: midnight-route, voicemail, untrue-step, half-light, worn-tape. tools/make_site.py --local VERSION OUT assembles the site from local builds.

Layout

base/                fm1-base (submodule): the platform, the host simulator, the browser emulator, the tools
lib/hdsp.h           the DSP the five share: FM and formant voices, Dattorro's plate, a tape echo, wow, beds, harmony
lib/hui.h            the panel and screen helpers they share: input, help cards, the header and knob bands
firmware/NAME/       one firmware: app.h, app.c (the UI and project), dsp/engine.[ch] (the sound, at -O2),
                     fm1.toml, words.tsv, tests/, docs/MANUAL.md, site/landing.md
tools/               build.sh, test.sh, get_toolchain.sh, get_sdk.sh, make_site.py
web/site.html        the flasher page (fm1-base's installer code inlined)
.github/workflows/   build every firmware, run its scenarios, publish the site, release on a tag

Continuous integration

Every push to main builds the five packages on GitHub's Linux runners (the toolchain runs natively there), runs each firmware's host-simulator scenarios, builds the browser emulators, assembles the site and publishes it on GitHub Pages (turn on Pages with Source "GitHub Actions" in the repository settings once). A tag vX.Y (matching the VERSION file) also makes a release with the five packages; the site is deployed from main only. Pull requests build and test without publishing.

Licence

The firmwares and the shared libraries are MIT (see LICENSE). fm1-base and felucca-bsp are MPL-2.0; the JieLi SDK files the package needs are Apache-2.0 and fetched at build time, never committed. M-VAVE and FM-1 are trademarks of their owners; this project is not affiliated with M-VAVE. The reverb is Jon Dattorro's plate ("Effect Design, Part 1", JAES 1997).