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PM_K-1 CircuitPython: add boot.py to guarantee the USB-MIDI port appears

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If the device isn't seen as a MIDI input (USB endpoint pressure from drive+serial+HID+MIDI),
boot.py disables the unused HID interface and enables usb_midi — copy it on and power-cycle.
Bundled into pm_k1_circuitpy.zip; documented in the README.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Me Here 2026-05-28 22:57:23 -05:00
parent 186b51ae23
commit b5584454b3
3 changed files with 18 additions and 3 deletions
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2
build.sh
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@ -39,7 +39,7 @@ pathlib.Path("dist/pico-main.py").write_text(pathlib.Path("pico/main.py").read_t
print("copied pico-main.py") print("copied pico-main.py")
import zipfile # PM_K-1 CircuitPython drive bundle (download → unzip onto CIRCUITPY) import zipfile # PM_K-1 CircuitPython drive bundle (download → unzip onto CIRCUITPY)
with zipfile.ZipFile("dist/pm_k1_circuitpy.zip", "w", zipfile.ZIP_DEFLATED) as z: with zipfile.ZipFile("dist/pm_k1_circuitpy.zip", "w", zipfile.ZIP_DEFLATED) as z:
for f in ("code.py", "programs.json", "font_s.bin", "font_m.bin", "font_l.bin", "README.md"): for f in ("code.py", "boot.py", "programs.json", "font_s.bin", "font_m.bin", "font_l.bin", "README.md"):
z.write("pico-cp/" + f, f) z.write("pico-cp/" + f, f)
z.write("dist/editor.html", "editor.html") # offline copy of the editor, on the drive z.write("dist/editor.html", "editor.html") # offline copy of the editor, on the drive
print("zipped pm_k1_circuitpy.zip") print("zipped pm_k1_circuitpy.zip")

9
pico-cp/README.md
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@ -28,8 +28,13 @@ same program‑string language as <https://metronome.varasys.io>.
The board also shows up as a **USB-MIDI** device and sends a note on every click (a GM drum note per The board also shows up as a **USB-MIDI** device and sends a note on every click (a GM drum note per
lane, velocity by accent). Open the [editor](https://metronome.varasys.io/editor.html) in **Chrome/Edge**, lane, velocity by accent). Open the [editor](https://metronome.varasys.io/editor.html) in **Chrome/Edge**,
click **🎹 Device audio**, grant MIDI access, then press play *on the device* — the editor voices the click **🎹 Device audio**, grant MIDI access, then press play *on the device* — the editor voices the
groove through its full synth, out your computer's speakers, locked to the device's clock. Set groove through its full synth, out your computer's speakers, locked to the device's clock. The button
`MUTE_BUZZER = True` in `code.py` if you'd rather silence the on-board buzzer while doing this. shows the connected device's name and pulses green on each note; set `MUTE_BUZZER = True` in `code.py`
if you'd rather silence the on-board buzzer while doing this.
If the editor says **no MIDI input is connected**, copy **`boot.py`** onto `CIRCUITPY` too and
**power-cycle** the Pico (`boot.py` only runs on a full reset). It frees a USB endpoint (drops the
unused HID interface) so the MIDI port is guaranteed to appear alongside the drive.
## Controls (same as the MicroPython build) ## Controls (same as the MicroPython build)

10
pico-cp/boot.py Normal file
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@ -0,0 +1,10 @@
# boot.py — runs once before USB connects (hard reset / power-cycle to apply).
# Guarantees the device shows up as a USB-MIDI port so the web editor's "Device audio"
# can hear it. We don't use HID, so disabling it frees a USB endpoint for MIDI on the
# Pico (which also exposes the CIRCUITPY drive + serial at the same time).
import usb_hid, usb_midi
try:
usb_hid.disable()
except Exception:
pass
usb_midi.enable()