`esw.stlink`

Reads log output from a board over the ST-LINKv3’s virtual COM port (VCP). This is the counterpart to the firmware logger in lib/util/Inc/logger.hpp.

Port Discovery

get_stlinkv3_port()

Scans serial ports and returns the ST-LINKv3 device path, or None if none is attached. Matches either on a description containing ST-Link/STLINK, or on ST’s USB vendor ID 0x0483 with a known ST-LINK product ID. Cached, so unplugging and replugging within one run will not be picked up.

Streaming

stream_serial_data(port_name: Path, baud_rate: int, log_level=logging.DEBUG)

Opens the port at 8N1 with a one second timeout and loops reading lines until interrupted. Decodes as UTF-8, replacing malformed bytes rather than raising, so line noise does not kill the session. Ctrl+C exits cleanly; a serial error is re-raised.

Output is re-leveled based on the prefix the firmware sends, so device log levels show up as Python log levels:

Device prefix	Logged as
DEBUG:	debug
INFO:	info
WARNING:	warning
ERROR:	error
anything else	info

Usage

Through the wrapper:

./scripts/monitor.sh --baud 115200 --log-level INFO

Or directly:

uv run --project tools python tools/scripts/monitor.py --baud 115200

Flag	Default	Meaning
--baud, -b	115200	must match the firmware’s UART configuration
--log-level, -l	INFO	one of DEBUG, INFO, WARNING, ERROR

The port is discovered automatically and is not a flag. If nothing is found, check that the board is connected and that you have permission to read the device. On Linux that usually means being in the dialout group.