9756538f16
Organizes 11 projects for Cerbo GX/Venus OS into a single repository: - axiom-nmea: Raymarine LightHouse protocol decoder - dbus-generator-ramp: Generator current ramp controller - dbus-lightning: Blitzortung lightning monitor - dbus-meteoblue-forecast: Meteoblue weather forecast - dbus-no-foreign-land: noforeignland.com tracking - dbus-tides: Tide prediction from depth + harmonics - dbus-vrm-history: VRM cloud history proxy - dbus-windy-station: Windy.com weather upload - mfd-custom-app: MFD app deployment package - venus-html5-app: Custom Victron HTML5 app fork - watermaker: Watermaker PLC control UI Adds root README, .gitignore, project template, and per-project .gitignore files. Sensitive config files excluded via .gitignore with .example templates provided. Made-with: Cursor
79 lines
2.6 KiB
Python
79 lines
2.6 KiB
Python
#!/usr/bin/env python3
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"""Debug wind extraction by examining actual packet bytes."""
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import struct
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PCAP_MAGIC = 0xa1b2c3d4
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def decode_float(data, offset):
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if offset + 4 > len(data):
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return None
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try:
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return struct.unpack('<f', data[offset:offset+4])[0]
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except:
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return None
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def read_pcap(filename):
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packets = []
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with open(filename, 'rb') as f:
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header = f.read(24)
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magic = struct.unpack('<I', header[0:4])[0]
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swapped = magic == 0xd4c3b2a1
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endian = '>' if swapped else '<'
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while True:
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pkt_header = f.read(16)
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if len(pkt_header) < 16:
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break
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ts_sec, ts_usec, incl_len, orig_len = struct.unpack(f'{endian}IIII', pkt_header)
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pkt_data = f.read(incl_len)
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if len(pkt_data) < incl_len:
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break
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if len(pkt_data) > 42 and pkt_data[12:14] == b'\x08\x00':
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ip_header_len = (pkt_data[14] & 0x0F) * 4
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payload_start = 14 + ip_header_len + 8
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if payload_start < len(pkt_data):
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packets.append(pkt_data[payload_start:])
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return packets
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packets = read_pcap("raymarine_sample.pcap")
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# Find packets of different sizes
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sizes_seen = {}
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for pkt in packets:
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plen = len(pkt)
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if plen not in sizes_seen:
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sizes_seen[plen] = pkt
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print("Examining wind data at known offsets:\n")
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for target_size in [344, 446, 788, 888, 1472]:
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# Find a packet close to this size
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for plen, pkt in sizes_seen.items():
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if abs(plen - target_size) <= 10:
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print(f"=== Packet size {plen} ===")
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# Show bytes around expected wind offsets
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if 340 <= plen <= 350:
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offsets = [0x00a0, 0x00a5, 0x00c3, 0x00c8]
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elif 440 <= plen <= 500:
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offsets = [0x00a7, 0x00ac, 0x00ca, 0x00b1]
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elif 780 <= plen <= 900:
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offsets = [0x0090, 0x00c5, 0x00ca, 0x00cf]
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elif 1400 <= plen <= 1500:
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offsets = [0x00fc, 0x0101, 0x0106]
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else:
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offsets = []
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for off in offsets:
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if off + 8 <= plen:
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hex_bytes = ' '.join(f'{b:02x}' for b in pkt[off:off+8])
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float_val = decode_float(pkt, off)
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# Also try treating as m/s and rad
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speed_kts = float_val * 1.94384 if float_val else 0
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dir_deg = float_val * 57.2958 if float_val else 0
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print(f" 0x{off:04x}: {hex_bytes} -> float={float_val:.4f} ({speed_kts:.1f} kts or {dir_deg:.1f}°)")
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print()
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break
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