Rust sibling of pico-scroll/app.py — the PM_G-1 'Grid' 17x7 LED metronome on a
plain RP2040 Pico (thumbv6m, not the Pico 2). LED-first milestone:
- IS31FL3731 driver: vendored bulk 144-byte framebuffer, one I2C block write per
frame (port of the CircuitPython Matrix; the is31fl3731 crate isn't used).
- Polymeter scheduler driven by track-format::schedule::lane_durs (the cross-impl
contract) + per-lane step clocks + tempo ramp + gap-trainer.
- 4-button input (A play/stop·hold=view, B next-track·hold=next-setlist, X/Y tempo).
- Built-in set lists; 3 views: Ticker (default), Grid, Pendulum.
- Ticker (user-designed): name infinite-scrolls left; BPM pinned right rotated 90
CCW = hundreds dot-bar (1 dot/100) + last 2 digits rotated. 130 -> 1 dot + '30'.
- Build scaffolding: rp2040-hal 0.10 + boot2, memory.x, build.sh + uf2.py (RP2040
family id). thumbv6m-none-eabi added to rust/Containerfile. Excluded from the
host workspace like pm-kit. Compiles clean -> 48 KB pm-grid.uf2.
Audio (USB-MIDI; the board has no speaker), live-sync, firmware push, practice log
and playback-flow auto-advance are deferred to the next milestone (as on pm-kit).
Also: delete COORDINATION.md (solo now); docs/rust-port.md updated with pm-grid
status + corrected Grid driver-matrix row.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adopt proper embedded tooling for the blank-screen debug (user has a Pi Debug Probe):
- flip-link linker (baked into pm-rust:2): stack overflow faults cleanly instead of
silently corrupting .bss/.data (the SPI buffer -> black screen class of bug).
- defmt + defmt-rtt + panic-probe: firmware logs boot/heap-free/display/parse/loop
heartbeat over RTT; panics print message+location. .cargo runner = probe-rs run.
- Restore the full live metronome (from 08b0940) as the instrumented target.
- deploy + serve pm-kit.elf (probe-rs decodes defmt strings from the ELF).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A third implementation of the track DSL alongside engine.js and app.py, validated
against the same tests/fixtures/track-format.json:
- rust/track-format/: pure parse()/serialize() codec (std + alloc for now; no_std is
a later refinement). Ports the app.py/engine.js semantics exactly — grouping,
subdivisions, swing, ghost, polymeter, euclid, GM note-number aliases, unknown->beep,
default groove (group-start accents), tempo clamp, empty->beep, and the playback-flow
tokens (rep/end/relative-goto). Carries vol/cd too, so it's the most spec-complete
of the three.
- tests/conformance.rs: the Rust adapter — reads the shared fixtures, asserts each
case's normalized form (number-tolerant deep-equal) + serialize idempotency.
- rust/Containerfile + run.sh: Rust toolchain in a container (mirrors hardware/eda/),
with the thumbv8m.main-none-eabihf target for the eventual RP2350 firmware. Never
on the host.
Verified: ./rust/run.sh -> cargo test -> conformance + idempotent both pass.
docs/rust-port.md Stage 1 marked done.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
