hondavert-dev/lib/core/protocol/kpro_parser.dart

import 'dart:typed_data';
import 'sensor_state.dart';
import 'temp_table.dart';
import 'neg8.dart';
import 'dtc_map.dart';
import 's300_parser.dart' show tpsPercent;

/// Parses a 128-byte KPro ECU response frame into a [SensorState].
/// Throws [ArgumentError] if frame length is wrong or NEG8 checksum fails.
SensorState parseKPro(Uint8List frame) {
  if (frame.length != 128) {
    throw ArgumentError('KPro frame must be 128 bytes, got ${frame.length}');
  }
  if (!validateFrame(frame)) {
    throw ArgumentError('KPro frame NEG8 checksum failed');
  }

  // Values marked KMGR were checked against KPro Manager on the bench
  // (2026-10-13, 7267 rpm frame); the PDF table's offsets for PA and BAT
  // turned out to be wrong, see below.

  // RPM: bytes 2..3 little-endian / 4. KMGR: 7267 rpm.
  final int rpmRaw = _readUint16LE(frame, 2);
  final double rpm = rpmRaw / 4.0;

  // VSS: byte 4 direct km/h
  final double vss = frame[4].toDouble();

  // TPS: byte 5, (raw - 25) / 2.04. KMGR: raw 163 -> 68 %.
  final double tps = tpsPercent(frame[5]);

  // MAP: bytes 6 (MAP1) and 33..34 (MAP2 L+H)
  final int map1Raw = frame[6];
  final int map2Raw = _readUint16LE(frame, 33); // MAP2L @33, MAP2H @34
  final double map = (map2Raw != 0) ? map2Raw / 10.0 : map1Raw.toDouble();

  // INJ: bytes 11..12 little-endian, µs -> ms. KMGR: 00 00 -> 0.00 ms (in
  // fuel cut). Byte order follows the L/H pairs; scale UNVERIFIED.
  final double inj = _readUint16LE(frame, 11) / 1000.0;

  // IGN: byte 13, (raw - 128) / 2 degrees. KMGR: raw 138 -> 5°.
  final double ign = (frame[13] - 128) / 2.0;

  // O2: byte 14 raw
  // O2: volts, raw × 5/256 as on the S300. UNVERIFIED for KPro.
  final double o2 = frame[14] * 5.0 / 256.0;

  // KRtrd: byte 21
  final int krtrd = frame[21];

  // SW bitmaps
  final int sw1 = frame[31];
  final int sw2 = frame[32];

  // ECT: byte 49. Table is tempXlt[raw] - 40, not +40 — see s300_parser.dart
  // for the reasoning (the declared -40..150 degC sensor range is only
  // reachable with subtraction).
  final double ect = (tempXlt[frame[49]] - 40).toDouble();

  // IAT: byte 50
  final double iat = (tempXlt[frame[50]] - 40).toDouble();

  // PA: byte 53, kPa. KMGR: raw 95 -> 95.0 kPa. (The PDF puts PA at 51.)
  final double pa = frame[53].toDouble();

  // BAT: byte 51, raw / 10. KMGR: raw 114 -> 11.40 V. (The PDF puts BAT at
  // 52; that byte read 232 -> "23.2 V".)
  final double bat = frame[51] / 10.0;

  // STRIM: byte 20, (raw - 128) / 1.28 %. KMGR: raw 128 -> 0 %.
  final double strim = (frame[20] - 128) / 1.28;

  // LTRIM — not explicitly listed in KPro; use 0
  const double ltrim = 0.0;

  // ETH — not in KPro spec; use 0
  const double eth = 0.0;

  // AFR: byte 25 (AFCMD at offset +19, then raw)
  final double afr = frame[25].toDouble();

  // ERR bytes: 18 bytes starting at offset 0x3E = 62
  final List<int> errBytes = List<int>.generate(18, (i) => frame[62 + i]);

  // AIN0–AIN7: bytes 0x52..0x61 (offset 82..97, uint16 LE each)
  final double ain0 = _readUint16LE(frame, 82).toDouble();
  final double ain1 = _readUint16LE(frame, 84).toDouble();
  final double ain2 = _readUint16LE(frame, 86).toDouble();
  final double ain3 = _readUint16LE(frame, 88).toDouble();
  final double ain4 = _readUint16LE(frame, 90).toDouble();
  final double ain5 = _readUint16LE(frame, 92).toDouble();
  final double ain6 = _readUint16LE(frame, 94).toDouble();
  final double ain7 = _readUint16LE(frame, 96).toDouble();

  // Gear — not in KPro frame, default 0
  const int gear = 0;

  // Flags. The PDF lists the bits LOWEST first. KMGR: SW1 = 0x50 with SCS
  // and FLR on -> SCS bit4, FLR bit6.
  // SW1: RVSLCK(0) BKSW(1) ACSW(2) ACCL(3) SCS(4) EPS(5) FLR(6) FANC(7)
  final bool brakeSwitch = (sw1 & 0x02) != 0;
  final bool acSwitch = (sw1 & 0x04) != 0;
  final bool fuelPump = (sw1 & 0x40) != 0; // FLR = fuel pump relay
  final bool fanOut = (sw1 & 0x80) != 0; // FANC
  // SW2: VTP(0) VTS(1) … MIL(3). KMGR: SW2 = 0x01/0x09 with VTP on, VTS
  // off, MIL on -> MIL is bit3 (the PDF list has a gap). MIL UNVERIFIED
  // beyond this one capture.
  final bool vtp = (sw2 & 0x01) != 0;
  final bool vtec = (sw2 & 0x02) != 0; // VTS = VTEC solenoid
  final bool mil = (sw2 & 0x08) != 0;
  // Knock = KRtrd > 0
  final bool knock = krtrd > 0;
  // Rev limit — not directly mapped in KPro SW; false
  const bool revLimit = false;
  // Launch — not in KPro SW; false
  const bool launch = false;

  return SensorState(
    rpm: rpm,
    vss: vss,
    map: map,
    tps: tps,
    inj: inj,
    ign: ign,
    ect: ect,
    iat: iat,
    bat: bat,
    o2: o2,
    gear: gear,
    eth: eth,
    pa: pa,
    afr: afr,
    strim: strim,
    ltrim: ltrim,
    ain0: ain0,
    ain1: ain1,
    ain2: ain2,
    ain3: ain3,
    ain4: ain4,
    ain5: ain5,
    ain6: ain6,
    ain7: ain7,
    mil: mil,
    fuelPump: fuelPump,
    fanOut: fanOut,
    vtec: vtec,
    knock: knock,
    revLimit: revLimit,
    launch: launch,
    brakeSwitch: brakeSwitch,
    acSwitch: acSwitch,
    vtp: vtp,
    iatError: anyDtcBit(errBytes, kproIatErrorBits),
    ectError: anyDtcBit(errBytes, kproEctErrorBits),
    o2Error: anyDtcBit(errBytes, kproO2ErrorBits),
    errBytes: errBytes,
    timestamp: DateTime.now(),
  );
}

int _readUint16LE(Uint8List frame, int offset) {
  return frame[offset] | (frame[offset + 1] << 8);
}