K230

K230 (lckfb 庐山派 CanMV) toolkit

K230 is the AI SoC on the lckfb 庐山派 dev board: Kanaan / Canaan K230, dual-core Cortex-A55 + KPU (NPU) + DPU + GPU + ISP, running CanMV (MicroPython on RT-Smart). Firmware is one or more *.py files dropped on the on-board SD card; /sdcard/main.py auto-runs at boot.

This skill bundles three workflows: deploy code, capture+analyze serial logs, screenshot the camera frame.

Hardware / port facts

• USB-CDC port on macOS: typically /dev/cu.usbmodem0010000001 (Kendryte CanMV, VID:PID 1209:abd1). On Linux: /dev/ttyACM*. Only ONE serial port — REPL and stdout share it.
• Baud rate: 115200 (CanMV default; not configurable on the K230 side).
• mpremote: pip3 install --user mpremote → usually ~/Library/Python/3.9/bin/mpremote on macOS, ~/.local/bin/mpremote on Linux.
• Boot entry: /sdcard/main.py auto-runs at reset, never exits until interrupted.
• /sdcard is only mounted after a hard reset (DTR/RTS pulse via mpremote ... reset). After a Ctrl-D soft reset, os.listdir("/sdcard") returns [] until next power cycle.
• sys.path on CanMV includes /sdcard — any .py file dropped there is importable from main.py.

Common pin / FPIOA cheatsheet (lckfb 庐山派)

LCD backlight is not a direct GPIO — it goes through a GP7101 I²C-to-PWM chip (7-bit address 0x58) on the I²C1 bus, then drives an SY7201ABC LED driver. Write a single byte (0–255 PWM duty) to control brightness: I2C(1, freq=400000).writeto(0x58, bytes([duty])).

mpremote quirks on K230

1. mpremote exec / raw-paste enter sequence often hangs. The K230 main loop frequently has nested try / except that swallows a single Ctrl-C, so the raw-paste handshake times out. Always send a raw 10×Ctrl-C burst via pyserial first, then use mpremote ... resume <subcommand> so mpremote attaches to the existing REPL without re-entering raw-paste.
2. mpremote connect ... reset also needs resume. Without it, mpremote tries to enter raw paste mode again and falls into the same trap.
3. Large files are slow over 115200 baud: ~5–10 KB/s, so a 150 KB main.py takes ~80 seconds. mpremote 1.28 has a content-hash check, so re-pushing an unchanged file is instant (Up to date: /sdcard/foo.py).
4. PWM ctor argument signatures vary by CanMV build. PWM(ch, freq, duty, enable=False) may raise "extra positional arguments given" — fall back to PWM(ch) + individual freq() / duty() / enable() setter calls. enable(0) is not always honored on the lckfb build — use duty(0) as the canonical "silent" state for buzzers.
5. I2C does not have I2C.I2C0 / I2C.I2C1 enum attributes on this CanMV build. Pass the bus number as a bare integer: I2C(1, freq=400000).

Workflow: deploying firmware

# Push every *.py in the current dir to /sdcard/ and reset.
python3 scripts/push_k230.py

# Or specify files explicitly
python3 scripts/push_k230.py main.py mod.py

# Use a different source dir
python3 scripts/push_k230.py --src-dir firmware/

# Skip the reset (useful when iterating fast)
python3 scripts/push_k230.py --no-reset

# Different port
PORT=/dev/ttyACM0 python3 scripts/push_k230.py

What the script does:

1. Interrupt running main.py — sends 10×Ctrl-C via raw pyserial.
2. Push — mpremote connect <port> resume fs cp <local> :/sdcard/<name> for each file. Uses resume so mpremote doesn't try to re-enter raw paste.
3. Reset — mpremote ... resume reset; falls back to Ctrl-D soft reset if that fails (less reliable: SD card may not re-mount).

Manual fallback when the script can't grab the REPL:

# 1. Raw Ctrl-C burst
python3 -c "import serial,time; p=serial.Serial('/dev/cu.usbmodem0010000001',115200,timeout=0.3); [p.write(b'\\x03') or time.sleep(0.15) for _ in range(10)]; p.close()"

# 2. Push
mpremote connect /dev/cu.usbmodem0010000001 resume cp main.py :/sdcard/main.py

# 3. Hard reset
mpremote connect /dev/cu.usbmodem0010000001 resume reset

Workflow: capturing serial logs

# 30s capture, default port, log → ./logs/k230-<ts>.log
python3 scripts/serial_log.py

# Force a soft-reset (Ctrl-D) before capture, to grab the full boot trace
python3 scripts/serial_log.py --reset --duration 60

# Stop a running main.py and capture REPL output
python3 scripts/serial_log.py --break-first --duration 20

# Collapse a noisy repeated line (e.g. face firmware spamming "NO_FACE")
python3 scripts/serial_log.py --dedup-pattern "NO_FACE"

Workflow: camera frame screenshot

# One-time: patch main.py to dump a stride-subsampled snapshot to /sdcard/snap.rgb every 3s
python3 scripts/screenshot.py --install

# Grab a frame → snaps/snap-<ts>.jpg
python3 scripts/screenshot.py

# Open in default viewer (macOS)
python3 scripts/screenshot.py --open

# Remove the patch
python3 scripts/screenshot.py --uninstall

This is a non-trivial dance: the K230 main loop holds the camera and deinits it on Ctrl-C, so by the time mpremote attaches the in-RAM frame is gone. The script side-channels a 700 KB raw frame through /sdcard/snap.rgb and decodes CHW → HWC + JPEG locally.

Use as a Claude Code skill

Drop this directory into .claude/skills/k230/ of any project, or clone it to ~/.claude/skills/k230/ for global availability. Claude Code's skill loader will pick up SKILL.md and surface this toolkit when the user mentions K230 / lckfb 庐山派 in conversation.

Prerequisites

pip3 install --user mpremote pyserial

That's it. No K230 SDK needed locally — all the heavy lifting (kmodel inference, camera, display) runs on the device.