nmea2000 #

NMEA 2000 marine protocol layer for Dart, built on top of package:j1939. Provides an Nmea2000Ecu with marine NAME defaults, mandatory PGN auto-responder, heartbeat, Fast Packet transport, and a field-level codec with NA/OOR sentinel handling.

Features #

• Marine ECU: Nmea2000Ecu with industry group 4, display defaults, automatic heartbeat
• Auto-responder: handles ISO Requests for Product Info, Config Info, and PGN List
• Fast Packet: automatic reassembly and transmission of multi-frame PGNs
• Field-level codec: decode() and encode() with resolution, offset, and sentinels
• PGN registry: 30+ pre-defined display PGNs (navigation, wind, heading, engine, electrical)
• Extensible: register custom PGN definitions at runtime
• Sealed events: same exhaustive switch support as package:j1939

Platform support #

Getting started #

Prerequisites #

• Dart SDK >= 3.0.0
• Linux with SocketCAN and a CAN interface (physical or virtual)
• CMake >= 3.16 and a C++23 compiler (required by the j1939 dependency)

Install #

dependencies:
  nmea2000: ^0.1.0

Virtual CAN setup #

sudo modprobe vcan
sudo ip link add dev vcan0 type vcan
sudo ip link set up vcan0

Usage #

Create an NMEA 2000 display node #

import 'package:nmea2000/nmea2000.dart';

void main() async {
  final ecu = await Nmea2000Ecu.create(
    ifname: 'vcan0',
    address: 0x80,
    modelId: 'My Display',
    softwareVersion: '1.0.0',
  );

  print('Claimed: 0x${ecu.address.toRadixString(16)}');
  // Heartbeat and auto-responder are already running.

  ecu.dispose();
}

Decode received PGN fields #

ecu.framesForPgn(130306).listen((frame) {
  final fields = decode(frame.data, windDataPgn);
  if (fields != null) {
    final speed = fields['windSpeed'] as double; // m/s
    final angle = fields['windAngle'] as double; // radians
    print('Wind: ${speed.toStringAsFixed(1)} m/s @ '
        '${(angle * 180 / 3.14159).toStringAsFixed(0)} deg');
  }
});

Encode and send a PGN #

final data = encode({
  'sid': 42,
  'windSpeed': 5.5,
  'windAngle': 0.785,
  'reference': 2,
}, windDataPgn);

await ecu.send(130306, priority: 6, dest: kBroadcast, data: data);

Exhaustive event handling #

ecu.events.listen((event) => switch (event) {
  FrameReceived(:final pgn, :final data) =>
    print('PGN 0x${pgn.toRadixString(16)} len=${data.length}'),
  AddressClaimed(:final address) =>
    print('Claimed 0x${address.toRadixString(16)}'),
  AddressClaimFailed() => print('Claim failed'),
  EcuError(:final errorCode) => print('Error: $errorCode'),
  Dm1Received(:final spn, :final fmi) => print('DM1 $spn/$fmi'),
});

Register custom PGNs #

final registry = Nmea2000Registry.standard()
  ..register([
    PgnDefinition(
      pgn: 65280,
      name: 'Proprietary',
      transport: 0,
      dataLength: 8,
      fields: [
        FieldDefinition(
          name: 'value',
          bitOffset: 0,
          bitLength: 32,
          resolution: 0.1,
          type: FieldType.unsigned,
        ),
      ],
    ),
  ]);

final ecu = await Nmea2000Ecu.create(
  ifname: 'vcan0',
  address: 0x80,
  registry: registry,
);

Full NAME field control #

final ecu = await Nmea2000Ecu.create(
  ifname: 'can0',
  address: 0x80,
  identityNumber: 0x1234,
  manufacturerCode: 0x1FF,
  deviceClass: 120,    // Display
  deviceFunction: 130, // Display
);

Pre-defined PGN categories #

Executables #

dart run nmea2000:demo                          # NMEA 2000 display node
dart run nmea2000:marine_sim --scenario=coastal_cruise  # traffic simulator

Testing #

dart test

License #

Apache 2.0 -- see LICENSE for details.