detect_all.py

#!/usr/bin/env python3
"""Detect ESP32 devkits attached to /dev/ttyACM* and /dev/ttyUSB* ports.

Prints one "device=port" line per detected device to stdout, e.g.:

    esp32c6=/dev/ttyACM1
    esp32s31=/dev/ttyUSB0

Device names are normalized the same way as detect.py (lowercased, dashes
stripped), matching the DEVICE values used by this project's Makefiles.
Intended to be consumed by shell scripts, e.g.:

    while IFS='=' read -r device port; do ...; done < <(python detect_all.py)
"""

import glob
import os
import re
import shutil
import subprocess
import sys

PORT_GLOBS = ("/dev/ttyACM*", "/dev/ttyUSB*")
ESPTOOL = "esptool"
PROBE_TIMEOUT = 30

# esptool emits ANSI color/cursor-control codes whenever the environment's
# TERM looks like a color terminal, even when stdout is a pipe. NO_COLOR
# disables that. ANSI_RE strips any escape codes that slip through anyway.
ESPTOOL_ENV = dict(os.environ, NO_COLOR="1")
ANSI_RE = re.compile(r"\x1b\[[0-9;]*[A-Za-z]")

CONNECTED_RE = re.compile(r"^Connected to (\S+) on (\S+):")
CHIP_TYPE_LINE_RE = re.compile(r"^Chip type:\s+(.+?)\s+\(revision v\d+\.\d+\)\s*$")
REVISION_RE = re.compile(r"revision (v\d+\.\d+)")


def find_ports():
    ports = []
    for pattern in PORT_GLOBS:
        ports.extend(glob.glob(pattern))
    return sorted(ports)


def normalize(name):
    return name.strip().lower().replace("-", "")


def detect_chip(port):
    try:
        result = subprocess.run(
            [ESPTOOL, "--port", port, "chip-id"],
            capture_output=True,
            text=True,
            timeout=PROBE_TIMEOUT,
            env=ESPTOOL_ENV,
        )
    except subprocess.TimeoutExpired:
        print(f"{port}: timed out probing for a chip", file=sys.stderr)
        return None

    stdout = ANSI_RE.sub("", result.stdout)

    chip_type = None
    chip_description = None
    revision = None
    for line in stdout.splitlines():
        match = CONNECTED_RE.match(line)
        if match:
            chip_type = match.group(1)
            continue
        match = CHIP_TYPE_LINE_RE.match(line)
        if match:
            chip_description = match.group(1)
        match = REVISION_RE.search(line)
        if match:
            revision = match.group(1)

    if chip_type is None or revision is None:
        print(f"{port}: no chip detected", file=sys.stderr)
        detail = result.stderr.strip() or stdout.strip()
        if detail:
            print(f"{port}: esptool output:\n{detail}", file=sys.stderr)
        return None

    return chip_type, chip_description or chip_type, revision


def main():
    if shutil.which(ESPTOOL) is None:
        print(f"error: '{ESPTOOL}' not found on PATH", file=sys.stderr)
        sys.exit(1)

    devices = {}
    for port in find_ports():
        detected = detect_chip(port)
        if detected is None:
            continue
        chip_type, chip_description, revision = detected
        print(f"{port}: detected {chip_description} revision {revision}", file=sys.stderr)

        device = normalize(chip_type)
        if device in devices:
            print(
                f"{port}: duplicate {chip_description} found, "
                f"already using {devices[device]}",
                file=sys.stderr,
            )
            continue

        devices[device] = port

    for device in sorted(devices):
        print(f"{device}={devices[device]}")


if __name__ == "__main__":
    main()