nmea 3.3.1

An extensible NMEA0183 parser, which also supports validating the checksum. Useful for reading data from GPS devices and other sensors.

example/example.dart

// ignore_for_file: avoid_print, unreachable_from_main

import 'dart:convert';

import 'package:nmea/nmea.dart' as nmea;

void main() {
  Stream.fromIterable([
    r'$--MSG,A,1,0,0,0,0*29',
    r"$PACME{'test':true}",
    r'$--NOT,REGISTERED,SENTENCE,TEST*1C',
    r'$CST,first,second',
  ])
      .transform(
    nmea.NmeaDecoder(onlyAllowValid: true)
      ..registerTalkerSentence(MsgSentence.id, (line) => MsgSentence(raw: line))
      ..registerProprietarySentence(
        AcmeProprietarySentence.id,
        (line) => AcmeProprietarySentence(raw: line),
      )
      ..registerCustomChecksumSentence(
        MyCustomSentence.id,
        (line) => MyCustomSentence(raw: line, validateChecksums: false),
      ),
  )
      .listen((sentence) {
    print('${sentence.raw} is a valid ${sentence.type.name} sentence');
  });

  // Output:
  // $--MSG,A,1,0,0,0,0*29 is a valid talker sentence
  // $PACME{'test':true} is a valid proprietary sentence
  // $CST,first,second is a valid custom sentence
}

class MsgSentence extends nmea.TalkerSentence {
  MsgSentence({required super.raw});

  static const String id = 'MSG';

  // You can access the fields in this talker sentence by their index
  String get field1 => fields[1];

  int get field2 => int.parse(fields[2]);
}

class AcmeProprietarySentence extends nmea.ProprietarySentence {
  AcmeProprietarySentence({required super.raw}) : super(manufacturer: id);

  static const String id = 'ACME';

  // custom data formatting is allowed in proprietary sentences
  String get json => rawWithoutFixtures;

  // custom validation by overriding [valid]
  // remember to call [super.valid]!
  @override
  bool get valid => super.valid && json.isNotEmpty;

  dynamic get data => jsonDecode(json);
}

class MyCustomSentence extends nmea.CustomChecksumSentence {
  MyCustomSentence({required super.raw, super.validateChecksums = true})
      : super(identifier: id);

  static const String id = 'CST';

  String get first => fields[0];

  String get second => fields[1];
}