KaraZajac
754af4134a
Brings KAT to 32 protocol decoders. Ported from the ProtoPirate reference and the D4C1-Labs/Flipper-ARF firmware: ProtoPirate (8): Kia V7, Ford V1, Ford V2, Ford V3, Chrysler V0, Honda Static, Honda V1, Land Rover V0. Flipper-ARF (6): Toyota, Land Rover RKE, Mazda Siemens, BMW CAS4, Porsche Cayenne, PSA2. Each decoder is gated (CRC / checksum / fixed markers / frame structure) so it cannot false-match existing protocols; every previously-decoding IMPORTS capture decodes unchanged. Real-capture decodes added for Ford V3 (LDV T80), Honda Static (Honda), Toyota (Camry NRZ variant), and PSA2 (Groupe PSA, serial 0x99EB25); the rest are validated by encode/decode round-trip and synthetic-frame tests. Also fixes a debug-only underflow panic in keeloq_common::keeloq_decrypt (15 - r underflowed; now wrapping_sub to match the reference's unsigned wrap; release behavior unchanged). Adds per-protocol docs, updates the README protocol table, capture metadata (encoding / RF / encryption), make-suggestion mapping, and CHANGELOG. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JEfaKqzB3T4qsrybwfEi73
63 lines
2.8 KiB
Markdown
63 lines
2.8 KiB
Markdown
---
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layout: default
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---
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# Ford V2 Protocol
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**Rust module:** `src/protocols/ford_v2.rs`
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**Reference:** `REFERENCES/ProtoPirate/protocols/ford_v2.c`
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## Overview
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Ford V2 uses Manchester encoding at 200/400 µs. 104 bits total (13 bytes). The frame begins with a
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16-bit Manchester sync that equals `0x7FA7` (the decoder matches the *inverted* shift register against
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`!0x7FA7`); those two sync bytes `0x7F 0xA7` head the 13-byte buffer. Decoded data bits are inverted
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before packing (`data_bit = !bit`). There is no CRC — structure is validated by the two sync bytes plus
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a known button code, so Ford V2 will not false-match.
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The Manchester decoder uses Flipper's transition table (same table as Ford V0), with Ford V2 polarity
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`level ? High : Low`.
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## Timing
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| Parameter | Value | Notes |
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|-----------|--------|-----------------------------|
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| Short | 200 µs | ±260 µs (te_delta) |
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| Long | 400 µs | ±260 µs |
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| Min bits | 104 | 13 bytes |
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| Preamble | ≥64 short pulses | before the sync |
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## Frame Layout (104 bits / 13 bytes)
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- **bytes 0–1:** sync `0x7F 0xA7`
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- **bytes 2–5:** serial (32-bit, big-endian)
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- **byte 6:** button — valid codes `0x10` (Lock), `0x11` (Unlock), `0x13` (Trunk), `0x14` (Panic), `0x15`
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- **bytes 7–8 + byte 9 MSB:** counter = `((b7 & 0x7F) << 9) | (b8 << 1) | (b9 >> 7)`; byte 7 MSB carries a button parity bit (refreshed by the encoder)
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- **bytes 9–12:** rolling/hop tail (stashed in `extra` so the encoder can rebuild the full frame)
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The exported `data` (Key) word is the top 8 bytes; bytes 8–12 (40 bits) are carried in `extra`.
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## RF
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- **Encoding:** Manchester (Ford V2 polarity `level ? High : Low`; decoded bits inverted)
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- **RF modulation:** FM (per ProtoPirate `SubGhzProtocolFlag_FM`)
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- **Encryption:** none — validated by sync bytes + valid button code
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- **Frequencies:** 315 MHz, 433.92 MHz
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## Decoder Steps
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1. **Reset** → a short pulse (~200 µs) begins the preamble.
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2. **Preamble** — count short pulses; after ≥64 shorts a long LOW pulse enters Sync.
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3. **Sync** — Manchester-decode bits into a 16-bit shift register; when it matches `!0x7FA7`, prime the two sync bytes and enter Data.
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4. **Data** — Manchester events feed the state machine; decoded bits are inverted and packed MSB-first into 13 bytes. At 104 bits the sync bytes and button are validated and the frame committed. A non-short/long pulse (gap) ends the attempt.
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## Encoder
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Supported (matches `subghz_protocol_encoder_ford_v2`). Rebuilds the 13-byte frame, applies the requested
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button, refreshes byte-7 parity, then emits 6 bursts of a 70-pair preamble + sync + 104 Manchester bits
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(encoder short 240 µs), separated by ~16 ms inter-burst gaps.
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## Validation
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Verified by an encode→decode round-trip / synthetic-frame check (no local capture available).
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