PRE-M8-T02: add read-only WarmteLink serial probe

This commit is contained in:
2026-08-22 18:06:15 +02:00
parent 22faeb45bb
commit 2992bbb0ef
5 changed files with 366 additions and 6 deletions
+202 -5
View File
@@ -1,15 +1,18 @@
"""Pure parsing helpers for DSMR and WarmteLink P1 telegrams.
Serial I/O deliberately belongs to the follow-up probe task. This module only
turns byte chunks into frames and parses the resulting telegrams.
"""
"""Read-only parser and command-line probe for DSMR and WarmteLink P1 telegrams."""
from __future__ import annotations
import argparse
from dataclasses import dataclass
from decimal import Decimal, InvalidOperation
from enum import StrEnum
import errno
import re
import sys
import time
from typing import BinaryIO, Callable, TextIO
import serial
_OBIS_LINE = re.compile(r"^(?P<code>\d+-\d+:\d+\.\d+\.\d+)(?P<values>(?:\([^)]*\))*)$")
@@ -189,3 +192,197 @@ def _parse_channels(fields: list[ObisField]) -> tuple[P1Channel, ...]:
)
for number, channel_fields in sorted(by_channel.items())
)
def build_parser() -> argparse.ArgumentParser:
"""Build the CLI parser for an explicitly selected, read-only serial device."""
parser = argparse.ArgumentParser(
description="Read-only WarmteLink P1 serial probe; it never writes to the device.",
epilog="Defaults are the locally measured WarmteLink 115200 7N1 framing, not DSMR defaults.",
)
parser.add_argument("--device", required=True, help="Explicit serial path, preferably /dev/serial/by-id/..."
)
parser.add_argument(
"--baudrate",
type=int,
default=115200,
help="Baud rate (default: 115200, the locally measured WarmteLink value).",
)
parser.add_argument(
"--bytesize",
type=int,
choices=(5, 6, 7, 8),
default=7,
help="Data bits (default: 7, locally measured; not the DSMR standard default).",
)
parser.add_argument(
"--parity",
choices=("N", "E", "O", "M", "S"),
type=lambda value: value.upper(),
default="N",
help="Parity (default: N, locally measured; not the DSMR standard default).",
)
parser.add_argument(
"--stopbits",
type=float,
choices=(1, 1.5, 2),
default=1,
help="Stop bits (default: 1, locally measured; not the DSMR standard default).",
)
parser.add_argument(
"--duration",
type=_positive_duration,
default=600.0,
help="Maximum capture time in seconds (default: 600).",
)
parser.add_argument(
"--show-changes",
action="store_true",
help="After the first frame, print only OBIS fields whose values changed.",
)
parser.add_argument(
"--raw-output",
type=argparse.FileType("wb"),
help="Optional path for the exact raw bytes read from the serial device.",
)
return parser
def _positive_duration(value: str) -> float:
try:
duration = float(value)
except ValueError as exc:
raise argparse.ArgumentTypeError("duration must be a positive number") from exc
if duration <= 0:
raise argparse.ArgumentTypeError("duration must be greater than zero")
return duration
def _serial_error_message(exc: BaseException) -> str:
"""Return a practical, non-root diagnostic for a serial open/read failure."""
error_number = getattr(exc, "errno", None)
message = str(exc)
if error_number == errno.EACCES or "permission denied" in message.lower():
return f"serial permission denied: {message}. Add your user to the dialout group; do not run it as root."
if error_number == errno.EBUSY or "resource busy" in message.lower():
return f"serial device is busy: {message}. Close the program currently using this device and retry."
if error_number in {errno.ENODEV, errno.ENOENT, errno.EIO}:
return f"serial device disconnected or unavailable: {message}. Check the cable and --device path."
return f"serial I/O failed: {message}. Check the cable, device path, and serial framing settings."
def _format_field(field: ObisField) -> str:
raw_values = ", ".join(field.raw_values) or "<no values>"
value = f" parsed={field.value} {field.unit or ''}" if field.value is not None else ""
return f" {field.code}: {raw_values}{value}".rstrip()
def _print_telegram(
telegram: P1Telegram,
frame_number: int,
cadence: float | None,
previous_fields: dict[str, tuple[str, ...]],
show_changes: bool,
output: TextIO,
) -> dict[str, tuple[str, ...]]:
cadence_text = "first frame" if cadence is None else f"cadence={cadence:.1f}s"
print(
f"frame {frame_number}: {telegram.integrity.value}; bytes={len(telegram.raw)}; {cadence_text}",
file=output,
)
print(f" integrity: {telegram.integrity_reason}", file=output)
current_fields = {field.code: field.raw_values for field in telegram.fields}
fields = telegram.fields
if show_changes and previous_fields:
fields = tuple(field for field in fields if previous_fields.get(field.code) != field.raw_values)
print(f" changed fields: {len(fields)}", file=output)
for field in fields:
print(_format_field(field), file=output)
for channel in telegram.channels:
print(
f" channel {channel.number}: device_type={channel.device_type or '<unknown>'}; "
f"readings={len(channel.readings)}",
file=output,
)
return current_fields
SerialFactory = Callable[..., serial.Serial]
def run_probe(
args: argparse.Namespace,
*,
serial_factory: SerialFactory = serial.Serial,
clock: Callable[[], float] = time.monotonic,
output: TextIO = sys.stdout,
error_output: TextIO = sys.stderr,
) -> int:
"""Capture and report frames until duration elapses or the user interrupts.
The only operation on ``serial_port`` is ``read``. It is always closed,
including after an interrupt, timeout, or a read error.
"""
raw_output: BinaryIO | None = args.raw_output
serial_port: serial.Serial | None = None
try:
serial_port = serial_factory(
port=args.device,
baudrate=args.baudrate,
bytesize=args.bytesize,
parity=args.parity,
stopbits=args.stopbits,
timeout=1,
)
framer = TelegramFramer()
deadline = clock() + args.duration
frame_number = 0
last_frame_at: float | None = None
previous_fields: dict[str, tuple[str, ...]] = {}
while clock() < deadline:
chunk = serial_port.read(4096)
if not chunk:
continue
if raw_output is not None:
raw_output.write(chunk)
raw_output.flush()
for frame in framer.feed(chunk):
now = clock()
telegram = parse_telegram(frame)
frame_number += 1
cadence = None if last_frame_at is None else now - last_frame_at
previous_fields = _print_telegram(
telegram,
frame_number,
cadence,
previous_fields,
args.show_changes,
output,
)
last_frame_at = now
return 0
except KeyboardInterrupt:
print("capture interrupted; serial device closed", file=output)
return 0
except (serial.SerialException, OSError) as exc:
print(_serial_error_message(exc), file=error_output)
return 1
finally:
if serial_port is not None:
serial_port.close()
if raw_output is not None:
raw_output.close()
def main(argv: list[str] | None = None) -> int:
"""Run the command-line probe."""
args = build_parser().parse_args(argv)
return run_probe(args)
if __name__ == "__main__": # pragma: no cover - exercised through main()
raise SystemExit(main())