Audio (the Scroll Pack has no speaker, so MIDI is the only path):
- usb-device 0.3 + usbd-midi 0.5 on the rp2040-hal UsbBus; enumerates as a
class-compliant MIDI device 'PM_G-1 Grid'.
- tick() emits a GM note-on per lane hit on channel 10 (note from the ported
SOUND_GM map, velocity by level) via send_bytes([0x09,0x99,note,vel]) — raw
4-byte packets, so arbitrary GM drum notes work without the named Note enum.
- USB polled every loop iteration AND during the boot splash (so the host can
enumerate during the ~2.5s animation).
Debug: defmt/defmt-rtt + panic-probe + flip-link; runner probe-rs run --chip
RP2040 (Pi Debug Probe). build.sh emits pm-grid.uf2 + pm-grid.elf; deploy serves
both; key info! log points + 1Hz heartbeat.
Web: drop CircuitPython from the PM_G-1 product. info-grid.html features the
Rust .uf2 download + accurate controls/views (X/Y swap, Ticker); build.sh +
deploy.sh no longer bundle/serve pm_g1_circuitpy.zip or pico-scroll-app.{py,mpy}.
pico-scroll/ stays as the reference port; editor FW_PATHS.G left for graceful
degradation.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
New form factor: a plain RP2040 Pico + Pico Scroll Pack (PIM545) -- a 17x7
single-colour LED matrix + 4 buttons. The 7x17 matrix maps onto the editor's
lane x step pad grid.
- pico-scroll/: CircuitPython firmware (DEVICE_ID "G"). Engine/scheduler/SysEx/
live-sync copied verbatim from pico-explorer (engine byte-identical, so it stays
on the track-format conformance lineage); vendored bulk-framebuffer IS31FL3731
driver (pins/map verified from pimoroni-pico); three LED views (Grid/Pendulum/BPM);
4-button input. Audio over USB-MIDI (no onboard speaker); optional P_BUZZER.
- grid.html + info-grid.html: widget page (canvas mirrors the 3 LED views) + spec
page with a ~$29 BOM.
- Registered in build.sh (precompile + ASCII assert + pm_g1_circuitpy.zip), deploy.sh,
embed.js, embed.html, index.html gallery, and both editors' FW_PATHS (device id G).
- docs/rust-port.md: core/driver architecture (pm-core no_std engine+protocol; per-board
drivers behind embedded-hal/embedded-graphics traits). CLAUDE.md + livesync-protocol.md
note the new edition + device id.
Python firmware stays in parallel with Rust (no abandonment yet).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
