Munchi Tempo

CHOMPI TEMPO 1.0 on Ableton Move. A groovebox: a chromatic sample engine and a slice engine playing side by side, a pattern generator for each, a clock-synced delay that blends into diffusion reverb, and A/B snapshots. It runs the actual TEMPO firmware code.

Munchi Tempo is a Schwung standalone tool. Launched from Schwung's Tools menu, it stops Move and runs the whole device itself (pads, knobs, buttons, lights, screen, audio). Back twice hands Move back. Its siblings are Munchi Tape (the CHOMPI's sampler and looper) and Munchi Wave (its wavetable synth).

It is a port of the firmware CHOMPI Club released as open source (CHOMPI-Club/CHOMPI, MIT). It is not an official CHOMPI Club release; see Credits.

→ The manual: a first session, both engines, the pattern generator, effects, slots and snapshots, every control.

At a glance

• CHROMA: one sample across the keyboard, 8 voices, two octaves below on Shift + Down
• SLICE: one sample cut into 16 slices on the white keys; black keys are rests
• A pattern generator per engine: arp styles, rest patterns, latch, freestyle, key sustain, randomness, clock division; tap tempo, MIDI clock in and out
• Clock-synced delay / diffusion reverb with randomness, feedback, freeze and a send per engine; output compressor and saturation
• Record from the mic, line in or Munchi Tempo itself; 14 slots per engine; snapshots A and B
• The sample folders, presets.json and options.json are in TEMPO's own formats, so they move to and from a CHOMPI's SD card

Quick start

Move	Does
Pads	the keyboard, two octaves as piano rows
Up / Down	SLICE / CHROMA engine
Steps 1–15, jog	slots (15 = the buffer)
Step 16	snapshot A/B (hold: copy)
Knobs, page 1	Speed, Start, End, Attack, Release, Level, Filter, Lofi
Knobs, page 2 (Right)	Delay, FX Mix, FX Random, Feedback, Pan, Tempo, Arp Random, Comp
Volume knob	Volume (Shift: input gain)
Play / Loop	pattern generator / latch (Shift: arp style / rests)
Sample	record (Shift: mic / line / resample)
Capture / Copy / Delete + step	save the buffer / copy / erase a slot
Track 1–4	tap tempo, sample loop, sustain, input monitoring
Mute	freeze the delay
Menu	settings
Back ×2	exit

The mic is only heard on headphones: Move's mic sits next to its speaker.

Install

From a release: download munchi-tempo-module.tar.gz from the latest release and install it with the Schwung web manager's custom-module upload, or paste this repository's URL into its custom install. From a build:

./scripts/build.sh      # fetches the factory card, cross-compiles in Docker
./scripts/install.sh    # copies dist/munchi-tempo to the Move

Then Tools menu (Shift + Volume + Step 13) → Munchi Tempo, or pick it as the boot target on the web manager's Boot page.

How it is built

Path	What
src/engine/tempo/	TEMPO's engines, pattern generator, clock, delay, effects and snapshots, from the firmware. Edited files keep their originals in tempo/upstream/; tempo/shim/ stands in for libDaisy and the CHOMPI board
src/engine/munchi_tempo.*	the firmware's page logic (NormalPage, MenuPage, ui.h, MidiManager's input), presets, options, the clock timer
src/engine/tempo_samples.cpp	the sample card: loading (any WAV format, converted to 48 kHz stereo) and a worker for every write
src/engine/resampler.h	the engine runs at its native 48 kHz; this converts to and from Move's 44.1 kHz
src/standalone/	the SPI loop, the Move control mapping, lights and screen
scripts/fetch-card.sh	fetches the factory card from the CHOMPI repo at a pinned commit
tests/	render.cpp (scripted events in, a WAV out) and surface_test.cpp (every Move control through the surface, with the screen as ASCII)

./scripts/fetch-card.sh build/card
FLAGS="-std=c++17 -O2 -Wno-vla -Isrc -Isrc/engine -Isrc/engine/tempo/shim -Isrc/engine/tempo"
ENGINE="src/engine/munchi_tempo.cpp src/engine/tempo_samples.cpp src/engine/daisysp/*.cpp"
c++ $FLAGS tests/render.cpp $ENGINE -o build-host/render
c++ $FLAGS tests/surface_test.cpp src/standalone/surface.cpp src/standalone/font.cpp $ENGINE -o build-host/surface_test
MUNCHI_CARD=/tmp/scratch-card ./build-host/render build/card tests/scripts/pattern.txt out.wav
./build-host/surface_test build/card /tmp/scratch-card2

Credits

• CHOMPI TEMPO 1.0: CHOMPI Club / Chase Bliss. MIT. The CHOMPI name, logo and character are CHOMPI Club's trademarks and are not licensed; this port is named Munchi Tempo for that reason.
• DaisySP: Electrosmith. MIT.
• Reverb, FX engine, limiter: Émilie Gillet, Mutable Instruments. MIT.

See THIRD_PARTY.md. Munchi Tempo itself is MIT (LICENSE).