fm1-wheel — hardware manual

Português · English

Tonewheel organ firmware for the M-VAVE FM-1, derived from setBfree, running on fm1-base.

1Install

The firmware is installed over USB-MIDI. Connect the FM-1 with a USB data cable and close any other application using its MIDI ports.

make device          # builds app/build/fm1-wheel.fwsc
make install         # shows the device and asks before writing

You can also use the project's web installer (Chrome/Edge) or run fm1_install.py directly. Installing firmware is at your own risk. Keep the official firmware and the recovery tools (fm1-base/bsp/tools/fm1_rescue.py, FM-1-transporter) at hand.

If the install is interrupted, the FM-1 stays in update mode and the same command finishes the write. To go back to the official firmware, use M-VAVE's updater or the web installer.

2Power on and play

The FM-1 has 27 keys (F3–G5), 7 encoders, 14 buttons, a MASTER pot and a 240×240 screen.

• The keys play the upper manual by default.
• OCT- / OCT+ transpose the built-in keyboard by up to ±2 octaves. External MIDI is not transposed by these buttons.
• The MASTER pot controls the output level.
• An external MIDI controller (USB or TRS) can play any manual; see section 5.

The screen shows:

• header: name, the note that is sounding, and CPU load;
• body: selected manual, registration, percussion, vibrato and the nine drawbar columns with the 16', 5⅓', 8', 4', 2⅔', 2', 1⅗', 1⅓', 1' footages;
• footer: octave, page, volume, rotor, SAVE state, drive and reverb.

3Buttons and encoders

Encoders

On page 2, K1 edits the 1' bar and K2–K4 control percussion (on/off), harmonic (2nd/3rd) and decay (fast/slow).

Buttons

The labels printed on the FM-1 are the stock ones; the screen shows the real function of each control.

Factory registrations

The registration is applied to the selected manual (ALGO/EDIT).

4Drawbar-key mode (the keyboard as a controller)

GLO turns on/off the mode in which the 27 keys stop playing and edit the drawbars of the selected manual. It is the equivalent of the programming mode on older clonewheel organs.

• Mode on: the built-in keys do not play; each press pushes or pulls a drawbar by one position. External MIDI keeps playing — you can play from a controller and use the FM-1 keyboard to edit the registration.
• Mode off: the keys play normally again.
• The mode is not saved: it starts off at the next boot.
• Drawbar changes mark SAVE; press SAVE to store them.

Key map

Each pair flat (black key) / natural (white key) controls one drawbar:

• F3, C4, F4 and C5 are ignored.
• D#5, E5, F5, F#5 and G5 are free (no function in this version).
• In drawbar mode all 18 control keys light equally; the ignored/free keys stay dark. The key color (black = push, white = pull) shows the direction.
• The bar grows from top to bottom: 0 = fully pushed in, 8 = fully pulled out (maximum volume).
• Each press changes one step (0..8). The value appears in the corresponding column on the screen; at 0 or 8 the key does not go past the limit.
• The edited manual is the one shown at the top of the screen (UPPER/LOWER/PEDAL); use EDIT or the ALGO encoder to change it.

To play from the built-in keyboard again, press GLO again. If a key is held while switching, it is released and only sounds again after being released and pressed again.

5MIDI

The FM-1 has USB-MIDI (in/out) and a TRS-MIDI input; there is no DIN output.

Control Changes

Program Change 0–7 selects one of the eight registrations.

The drawbar map is setBfree's (inverted: 0 = maximum). An external drawbar controller works without extra configuration, including in drawbar-key mode.

6What is saved

SAVE writes to flash:

• the octave;
• the swell;
• all 27 drawbars (upper/lower/pedal);
• percussion (on/off, 2nd/3rd, fast/slow);
• the selected registration;
• vibrato (mode);
• drive and character;
• reverb;
• rotor (stop/slow/fast).

Not saved: drawbar-key mode, the edit page and the selected manual (they return to their defaults at boot).

7Troubleshooting

8Development

make build-host      # host simulator
make test-host       # app tests (keys, drawbars, MIDI, persistence)
make web             # browser emulator (Emscripten)
make serve-web       # http://localhost:8790/
make compare         # A/B against setBfree
make device          # firmware for the FM-1
make install         # writes it to the connected FM-1

The web emulator runs the same C code as the firmware; use Cmd+Shift+R to load a new wasm after make web.

9Licence and trademarks

The firmware is GPL-3.0-or-later. setBfree is GPL-2.0-or-later; fm1-base and felucca-bsp are MPL-2.0; the JieLi SDK files are Apache-2.0. See LICENSING.md and LICENSES/.

“Hammond”, “B3” and “Leslie” are trademarks of their owners. fm1-wheel is not affiliated with or endorsed by them. Use “tonewheel organ” and “rotary speaker” in public material.

Development

The fm1-wheel code, DSP port, tests, tools and documentation were developed with OpenCode using DeepSeek V4.1 Flash, under human direction and review.

10M-VAVE SMK-37 Pro

The same firmware also builds for the SMK-37 Pro:

make smk37
# app/build/smk37/fm1-wheel-smk37.fwsc

The SMK has 37 keys (C3–C6), 16 pads, four faders and eight encoders. The middle 27 keys are the FM-1's F3–G5. Drawbars use the four faders on three pages:

FADER BANK and pads 9–11 select the page; pads 1–8 recall the factory registrations. Values remain 0–8 and fill from the top down. Faders use soft takeover. GLOBE turns the fader/pad controls on and off; the keys keep playing. There is no TRS MIDI in on the SMK: use USB-MIDI. See SMK37.md for installation, safety and the hardware bring-up checklist.