bug-hunter-controller

Zephyr RTOS firmware for the Seeed XIAO nRF52840 (Zephyr board: xiao_ble), built against Zephyr v4.4.0 via west.

• Zephyr SDK 1.0.1+ installed (cross-compiler toolchain + host tools)
• Python venv with west installed, at the workspace root (one level above this repo)
• Zephyr source + modules fetched into the workspace (west update)

See west.yml for the pinned Zephyr revision and required modules (cmsis_6, hal_nordic).

The Python venv lives in the workspace root (one level above this repo), so from inside this repo activate it with ../.venv:

cd bug-hunter-controller
source ../.venv/bin/activate
west build -b xiao_ble .

The prompt should now start with (.venv). Activation only applies to the current terminal, so repeat it in each new shell — otherwise west will not be found.

This reuses the existing build/ directory and only rebuilds what changed. For a full clean rebuild, add -p always:

west build -p always -b xiao_ble .

A successful build produces build/zephyr/zephyr.uf2.

1. Enter bootloader mode — double-tap the reset button quickly (both presses within ~0.5s). If it doesn't take, unplug the USB cable, press and hold reset, plug the cable back in while still holding it, then release after ~1-2s.
2. The board mounts as a USB mass-storage drive (may be labeled XIAO-SENSE even on a plain, non-Sense board — this is a known bootloader labeling quirk, not an indication of which variant you have).
3. Copy the firmware onto the mounted drive:

   cp build/zephyr/zephyr.uf2 /media/$USER/XIAO-SENSE/

4. The drive disappearing right after the copy is success, not an error — the bootloader flashes the file and auto-resets into the new application.

The console is native USB CDC-ACM (/dev/ttyACM0), not a physical UART bridge. Every board reset tears down and recreates this device, so a plain screen/minicom session will die on each reset/reflash. To get a monitor that survives resets without manual reattachment:

while true; do
  [ -e /dev/ttyACM0 ] && cat /dev/ttyACM0
  sleep 0.3
done

Ctrl-C to stop. If /dev/ttyACM0 is not accessible, add yourself to the dialout group (sudo usermod -aG dialout $USER) and start a new session.

The firmware drives two outputs, switched by commands on the same USB serial port as the console:

Each command is a 3-byte frame: 0x11, a mask/value byte (high nibble = which outputs to change, low nibble = their new values), then the bitwise inverse of that byte as a check. Invalid frames are silently dropped; there is no reply.

Requires Python 3 and pyserial (pip install pyserial). Works on Windows and Linux.

python tools/set_outputs.py --list              # list serial ports
python tools/set_outputs.py COM5 all=on         # D1 and D2 on
python tools/set_outputs.py COM5 all=off        # both off
python tools/set_outputs.py COM5 0=on           # D1 on, D2 unchanged
python tools/set_outputs.py COM5 0=on 1=off     # D1 on, D2 off

Replace COM5 with the board's port (on Linux, /dev/ttyACM0). Outputs not named keep their current state. On Windows only one program can open a COM port at a time, so close any serial monitor on that port first, or the script fails with "Access is denied".