metronome/pico-cp/README.md
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

55 lines
2.9 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# PM_K1 "Kit" — CircuitPython edition (USB drive + editor)
The **CircuitPython** firmware for the 52Pi EP0172 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 programstring 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 oneclick "Save to device" and USBMIDI audiotocomputer
> are landing in later phases. The simpler **MicroPython** firmware (`../pico/main.py`) remains the
> rocksolid fallback — and the Pico can't be bricked (BOOTSEL → drag a MicroPython `.uf2` back).
## Install
1. **Flash CircuitPython:** hold **BOOTSEL**, plug in, and drop the CircuitPython `.uf2` for your board
onto the `RPIRP2` drive (<https://circuitpython.org/board/raspberry_pi_pico/> — or the Pico 2 / W
build). It reboots and a **`CIRCUITPY`** drive appears.
2. **Copy the files** onto `CIRCUITPY` (draganddrop — it's a normal drive now):
- `code.py` (this firmware — runs on boot)
- `programs.json` (your grooves)
3. It starts immediately. Editing `programs.json` (or resaving it from the editor) makes CircuitPython
**autoreload** with the new tracks.
## Controls (same as the MicroPython build)
- **Touch:** onscreen `◀◀ / ▶ / ▶▶` (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
```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 antialiased blobs as the MicroPython build (see `../pico/gen_font.py`).