Me Here b419ad0daa Phase 1: CircuitPython firmware (USB-drive edition) for the Kit

New pico-cp/ — a CircuitPython port of the PM_K-1 firmware so the Pico mounts as a
CIRCUITPY drive carrying its code + tracks (the MicroPython pico/main.py stays the
simple fallback):
  - pico-cp/code.py: displayio BusDisplay driving ST7796 via a custom init_sequence;
    smooth anti-aliased text via displayio Bitmap+Palette (reuses the baked font blobs);
    vectorio rects for dots/buttons; DIY GT911 touch (16-bit regs, edge-detected);
    pwmio buzzer, analogio joystick, digitalio buttons, optional neopixel RGB; the
    polymeter engine on a time.monotonic_ns scheduler. Reads /programs.json (falls back
    to baked defaults); CircuitPython auto-reloads on file change.
  - pico-cp/programs.json: the 23 default grooves. pico-cp/README.md: flash + calibrate.
  - build.sh/deploy.sh: bundle + serve /pm_k1_circuitpy.zip. info-kit.html: experimental
    'CircuitPython edition — USB drive' section.

Verified in CPython (stubbed displayio): init sequence well-formed, parser handles the
grooves incl. (3,8) euclid + @-4 gain, and code.py's actual make_text renders identical
smooth AA text. Hardware bits (panel/touch/MIDI) await on-board testing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

2026-05-28 21:10:34 -05:00

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PM_K‑1 "Kit" — CircuitPython edition (USB drive + editor)

The CircuitPython firmware for the 52Pi EP‑0172 Pico kit. Unlike the MicroPython version (../pico/main.py), this makes the Pico mount as a USB drive (CIRCUITPY) that carries the firmware and your tracks — so you can edit on the web and reprogram it without Thonny. It runs the same program‑string language as https://metronome.varasys.io.

Status: experimental, phase 1. This drives the screen/touch/joystick/buzzer and reads your grooves from programs.json. The editor's one‑click "Save to device" and USB‑MIDI audio‑to‑computer are landing in later phases. The simpler MicroPython firmware (../pico/main.py) remains the rock‑solid fallback — and the Pico can't be bricked (BOOTSEL → drag a MicroPython .uf2 back).

Install

Flash CircuitPython: hold BOOTSEL, plug in, and drop the CircuitPython .uf2 for your board onto the RPI‑RP2 drive (https://circuitpython.org/board/raspberry_pi_pico/ — or the Pico 2 / W build). It reboots and a CIRCUITPY drive appears.
Copy the files onto CIRCUITPY (drag‑and‑drop — it's a normal drive now):
- code.py (this firmware — runs on boot)
- programs.json (your grooves)
It starts immediately. Editing programs.json (or re‑saving it from the editor) makes CircuitPython auto‑reload with the new tracks.

Controls (same as the MicroPython build)

Touch: on‑screen ◀◀ / ▶ / ▶▶ (prev · play/stop · next) and − / TAP / +.
Joystick: up/down = tempo, left/right = previous/next groove.
Button A (GP15) play/stop · Button B (GP14) tap tempo.
RGB LED flashes each beat; buzzer clicks (accent/normal/ghost).

programs.json

{ "title": "PolyMeter",
  "programs": [ { "name": "Four on the floor", "prog": "t120;kick:4;snare:4=.x.x;hatClosed:4/2" } ] }

Each prog is a program string from the web editor. Add/replace entries and save — the device reloads.

Calibration (flip flags at the top of `code.py`)

Red/blue swapped: change MADCTL = 0x40 to 0x48.
Colours look negative: toggle INVERT_COLORS.
Taps land wrong: set TOUCH_DEBUG = True, watch the serial output, then set TOUCH_SWAP_XY / TOUCH_INVERT_X / TOUCH_INVERT_Y.
Joystick reversed: toggle JOY_INVERT_X / JOY_INVERT_Y.
Screen blank / garbled: the panel lot may differ; drop SPI_BAUD, and if it's a 240×320 ILI9341 instead of the 320×480 ST7796, the init/size need changing (this targets the 320×480 you have).
No RGB LED: the WS2812 needs the neopixel library on CIRCUITPY/lib (circup install neopixel) — everything else works without it.

If code.py ever errors, CircuitPython prints the traceback on the screen and over USB serial — copy that to me and I'll fix it.

The fonts are the same baked anti‑aliased blobs as the MicroPython build (see ../pico/gen_font.py).

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