chore(compose): add docker-compose.yml

services/collector/protocol_parser.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+"""
+FR-1.4 Data Transmission Protocol Parser (v1)
+12-byte binary packet: [0xAA][TYPE=0x02][LEN=8][TIMESTAMP(4)][RMS_DB(2)][FREQ_HZ(2)][CRC8(1)]
+"""
+
+import struct
+from typing import Optional, NamedTuple
+from dataclasses import dataclass
+
+
+class AudioMetrics(NamedTuple):
+    """Parsed audio metrics packet"""
+    timestamp_ms: int
+    rms_db: float
+    freq_hz: int
+    valid: bool = True
+
+
+@dataclass
+class ProtocolStats:
+    """Protocol statistics"""
+    packets_received: int = 0
+    crc_errors: int = 0
+    length_errors: int = 0
+    range_errors: int = 0
+
+
+class ProtocolParser:
+    """
+    Stream parser for FR-1.4 protocol with automatic resynchronization.
+    """
+
+    SOF = 0xAA
+    TYPE_AUDIO_V1 = 0x02
+    PAYLOAD_LEN = 0x08
+    PACKET_SIZE = 12
+
+    def __init__(self):
+        self.buffer = bytearray()
+        self.stats = ProtocolStats()
+
+    @staticmethod
+    def _crc8_atm(data: bytes) -> int:
+        """CRC-8/ATM: poly=0x07, init=0x00, refin=false, refout=false, xorout=0x00"""
+        crc = 0x00
+        for byte in data:
+            crc ^= byte
+            for _ in range(8):
+                if crc & 0x80:
+                    crc = ((crc << 1) ^ 0x07) & 0xFF
+                else:
+                    crc = (crc << 1) & 0xFF
+        return crc
+
+    def feed(self, data: bytes) -> list[AudioMetrics]:
+        """
+        Feed incoming bytes, return list of parsed packets.
+
+        Args:
+            data: Raw bytes from serial port
+
+        Returns:
+            List of successfully parsed AudioMetrics
+        """
+        self.buffer.extend(data)
+        packets = []
+
+        while len(self.buffer) >= self.PACKET_SIZE:
+            # Find SOF
+            sof_idx = self.buffer.find(self.SOF)
+            if sof_idx == -1:
+                # No SOF found, discard all but last byte
+                self.buffer = self.buffer[-1:]
+                break
+
+            # Discard bytes before SOF
+            if sof_idx > 0:
+                self.buffer = self.buffer[sof_idx:]
+
+            # Need at least 3 bytes for SOF + TYPE + LEN
+            if len(self.buffer) < 3:
+                break
+
+            packet_type = self.buffer[1]
+            payload_len = self.buffer[2]
+
+            # Validate TYPE and LEN
+            if packet_type != self.TYPE_AUDIO_V1 or payload_len != self.PAYLOAD_LEN:
+                self.stats.length_errors += 1
+                self.buffer.pop(0)  # Remove false SOF, retry
+                continue
+
+            # Full packet size = SOF(1) + TYPE(1) + LEN(1) + PAYLOAD(8) + CRC(1) = 12
+            total_len = 3 + payload_len + 1
+            if len(self.buffer) < total_len:
+                break  # Wait for more data
+
+            packet = bytes(self.buffer[:total_len])
+
+            # Verify CRC (over bytes 1..10: TYPE, LEN, payload)
+            crc_data = packet[1:11]
+            expected_crc = packet[11]
+            calculated_crc = self._crc8_atm(crc_data)
+
+            if calculated_crc != expected_crc:
+                self.stats.crc_errors += 1
+                self.buffer.pop(0)  # Remove bad packet, retry
+                continue
+
+            # Parse payload (little-endian)
+            timestamp_ms, rms_db_x10, freq_hz = struct.unpack_from('<IhH', packet, 3)
+
+            # Convert and validate ranges
+            rms_db = rms_db_x10 / 10.0
+            valid = True
+            if not (-40.0 <= rms_db <= 80.0) or not (100 <= freq_hz <= 8000):
+                self.stats.range_errors += 1
+                valid = False
+
+            self.stats.packets_received += 1
+            packets.append(AudioMetrics(
+                timestamp_ms=timestamp_ms,
+                rms_db=rms_db,
+                freq_hz=freq_hz,
+                valid=valid
+            ))
+
+            # Remove processed packet
+            self.buffer = self.buffer[total_len:]
+
+        return packets
+
+    def get_stats(self) -> ProtocolStats:
+        """Get current statistics"""
+        return self.stats