README from GitHub, GPL-3.0

Mario Texture's GRANA

A granular sample player for the M-VAVE FM-1, in the spirit of the MicroGranny 2: four layers of samples played by a cloud of grains, lo-fi effects, arpeggiator, sequencer, 64 named presets and a browser editor to load your own samples and install the firmware.

Versione italiana: LEGGIMI.md

The interface (screen and editor) is in Italian; this page explains what the names mean.

Unofficial firmware: not made or endorsed by M-VAVE. It installs and uninstalls over USB; to go back to the stock firmware, reinstall it with the official updater or the FM-1 Firmware Hub. Use at your own risk.

Version 1.6.3. Tested on a real FM-1 (black keys).

Install

From the Releases page download the editor grana-editor-X.Y.Z.html and open it in Chrome or Edge (it needs Web MIDI and WebUSB).
Try GRANA in the page's simulator: it is the same code that runs on the FM-1.
Choose your samples (see below), connect the FM-1 over USB and press Installa (install). Stay on the tab until it is done.
GRANA + Bluetooth variant: with its checkbox the FM-1 connects by itself to a BLE-MIDI controller (SMC-Mixer, SMC-PAD…). Its code is longer, so it leaves a little less room for samples.

The packages grana-X.Y.Z.fwsc (and -bluetooth) in the Releases hold the stock sounds, for those who install with other tools.

Recovery: if something goes wrong, power the FM-1 on while holding OCT−: only the USB updater starts. The rescue/ folder has the tools and the instructions (rescue/LEGGIMI.txt, in Italian) for the worst case.

Samples

Factory bank (banca di fabbrica): lives inside the firmware, changes only by reinstalling (about 440 KB, 390 KB with Bluetooth).
User bank (banca utente): 276 KB in a separate area of the FM-1's memory; sent from the editor with Invia la banca utente all'FM-1, without reinstalling, and kept when GRANA is updated.
Each sample at 22 kHz or 11 kHz (half the space, even more grit) and HIFI (16 bit) or LOFI (8 bit) in RAM. All at 11 kHz you get about two minutes of samples; the editor shows the room left.
The user bank can be saved to and opened from a .grnb file (the bank exactly as the FM-1 stores it); presets go to a .grnp file from the Preset section.
Up to 48 samples in all. Eight stock sounds, synthesised by tools/make_samples.py.

The sound

Up to 4 layers played together (SOVRAPPOSTI) or split across the keyboard (SPLIT), each with its own pitch, start, area, pan, volume and share of grains.
Grains: size, density, spray, jitter, skip, direction, reverse, four windows; free or frozen scan, dice.
Multimode filter (24 dB ladder, 12 dB, band-pass, 12/24 dB high-pass, notch) with slow movement.
MODULAZIONE (modulation): VELVET (chorus, flanger, phaser and what lies between) or METALLO (ring modulator and frequency shifter).
NASTRO (tape): ping-pong echo, repeats in time or at random (beat repeat), reverse echoes, tape echo with wow and flutter, freeze.
Plate reverb (Jon Dattorro's figure) with shimmer; compressor; 12-bit output (or 16).
Two LFOs with many destinations, arpeggiator, 64-step sequencer, SCALES that snap the keys, drone, freeze, crush.
MIDI: USB and TRS jack always on, MIDI LEARN (32 mappings), clock in and out, RICEVI filter (all / clock only / one channel); SMC-Mixer over Bluetooth.

The pages

Each button opens its pages, pressed again it goes to the next; SELECT turns through all of them. KNOB 1–4 are the page's four parameters. Names as on the screen.

Button	Page	KNOB 1	KNOB 2	KNOB 3	KNOB 4
HOME	STRATI	STRATO 1	STRATO 2	STRATO 3	STRATO 4
	SPLIT	DISPOSIZIONE	SPLIT 1	SPLIT 2	SPLIT 3
	QUANTITA'	LIVELLO 1	LIVELLO 2	LIVELLO 3	LIVELLO 4
	PITCH STRATI	PITCH 1	PITCH 2	PITCH 3	PITCH 4
	INI/AREA 1-2	INIZIO 1	AREA 1	INIZIO 2	AREA 2
	INI/AREA 3-4	INIZIO 3	AREA 3	INIZIO 4	AREA 4
FX	FILTRO	MODO	FREQUENZA	RISONANZA	MOVIMENTO
	MODULAZIONE	TIPO	VELOCITA'	PROFONDITA'	MIX
	NASTRO	MODO	TEMPO	RITORNO	MIX
	NASTRO 2	VARIAZIONE	TONO	PASSO	RIP. A CASO
	RIVERBERO	MIX	CODA	TONO	MODULAZIONE
	RIVERBERO 2	SHIMMER	INTERVALLO	TONO	DIFFUSIONE
SEL	MOTO	POSIZIONE	AREA	SCAN	DIREZIONE
	MOTO 2	JITTER	SALTO	DADO	OGNI
ENV	FORMA	FINESTRA	REVERSE	ATTACCO	RILASCIO
	TASTIERA	RETRIG	TASTO	SCALA	TONICA
LFO	LFO 1	FORMA	VELOCITA'	INTENSITA'	DESTINAZIONE
	LFO 2	FORMA	VELOCITA'	INTENSITA'	DESTINAZIONE
	SPECIALI	DRONE	FREEZE	CRUSH	—
EDIT	GRANI	DIMENSIONE	DENSITA'	SPRAY	PITCH
GLO	VOLUMI	VOLUME 1	VOLUME 2	VOLUME 3	VOLUME 4
	PAN STRATI	PAN 1	PAN 2	PAN 3	PAN 4
	MIX	STEREO	COMPRESSORE	USCITA	VOLUME
ARP	ARP	MODO	DIVISIONE	OTTAVE	GATE
SEQ	SEQ	TEMPO	SWING	PASSI	DIVISIONE
GLO	MIDI	CLOCK	RICEVI	LEARN	CANCELLA
	BT (GRANA + Bluetooth only)	BLUETOOTH	DISPOSITIVO	MODO	AVVIO

A few words: STRATI layers · QUANTITA' share of grains · INI/AREA start and area · NASTRO tape · RIVERBERO reverb · MOTO motion · FORMA shape (envelope) · TASTIERA keyboard (SCALA scale, TONICA root) · SPECIALI specials · GRANI grains · VOLUMI volumes · USCITA output (12/16 bit) · RICEVI receive.

Other controls: HOME held = HOLD; SEL held = dice; ALGORITHM = sound of the first layer; PRESETS = the 64 presets; SAVE = save (the knobs write the name); PLAY/REC = sequencer; OCT−/OCT+ = octave.

Building

You need Linux x86-64 (or Docker), Python 3 with Pillow, the JieLi toolchain and three files of the JieLi AC79 SDK (uboot.boot, cfg_tool.bin, cfg/eq_cfg_hw.bin, Apache-2.0, not included here).

tools/get_toolchain.sh                         # the JieLi toolchain in ~/.jieli
export AC79_SDK=~/fw-AC79_AIoT_SDK             # with cpu/wl82/tools/ inside
./build.sh --release 1.6.3 [--bt]              # build/grana-1.6.3[-bluetooth].fwsc, build/grana-app[-bt].bin
sh web/build_wasm.sh                           # web/grana.wasm, the simulator (clang with wasm32)
python3 web/make_page.py 1.6.3 FM-1_956 FM-1_966   # web/grana-editor.html

Simulator tests: node tests/t16.mjs web/grana.wasm <1.5's grana.wasm> firmware/gen/bank_default.bin, node tests/t_smc.mjs web/grana.wasm firmware/gen/bank_default.bin, node tests/t_midi.mjs ….

Credits and licence

GRANA is by Mario Texture, written with the help of Claude (Anthropic). It is free software under GPL-3.0-only (LICENSE): whoever distributes a firmware built from here must give its source too, under the same licence.

Built on Dinghy (zvenson), which uses the platform of Felucca (Leo Kuroshita, Hügelton Instruments) as SLOOP (isod89) carries it. Bluetooth: Optimist's stack (w0ts), the glue after fm1-dock (Joakim Eriksson) and the SMC-Mixer mode after Hortator (DeadActive). Details in LICENSING.md.

"M-VAVE" and "FM-1" are trademarks of their owners.