NMEA-0183 Parser Library in Java for Android

This is a basic NMEA-0183 parser that processes bytes fed into its API. When a complete NMEA sentence is successfully read, application-level handlers are invoked.

Quick Example

This is the simplest scenario: using the DefaultNmeaHandler class. DefaultNmeaHandler implements the contract INmeaHandler, which defines support for the following NMEA-0183 data types:

• GGA : Global Positioning System Fix Data
• GSA : Satellite status
• GSV : Satellites in view
• GST : GPS Pseudorange Noise Statistics
• HDT : NMEA heading log
• RMC : Recommended Minimum data for gps
• VTG : Track made good and ground speed

DefaultNmeaHandler implements the contract by invoking the event handler LogNmeaMessage each time a supported NMEA sentence is successfully parsed.

    // ... Create an object to handle parsed NMEA messages
    DefaultNmeaHandler nmeaHandler = new DefaultNmeaHandler();
    nmeaHandler.set_OnLogNmeaMessageHandler( new DefaultNmeaHandler.OnLogNmeaMessageHandler() {
        @Override
        public void OnLogNmeaMessage( String msg ) {
            Log.i("NmeaTester","New NMEA Message: " + msg );
        }
    } );

    // ... Create the NMEA receiver
    NmeaReceiver nmeaReceiver = new NmeaReceiver( nmeaHandler ) ;

    // ... Attach handler for NMEA messages that fail NMEA checksum verification
    nmeaReceiver.setMessageHandlers( new NmeaReceiver.MessageHandlers() {
        @Override
        public void OnNmeaMessageFailedChecksum( byte[] bytes, int index, int count, byte expected, byte actual ) {
            String sentence = new String(bytes, index, count, StandardCharsets.US_ASCII ) ;
            Log.e("NmeaTester", "Failed Checksum: " + sentence + "; expected "+expected+" but got " + actual );
        }

        @Override
        public void OnNmeaMessageDropped( byte[] bytes, int index, int count, String reason ) {
            String sentence = new String(bytes, index, count, StandardCharsets.US_ASCII ) ;
            Log.i("NmeaTester","Bad Syntax: "+sentence+"; reason: "+reason );
        }

        @Override
        public void OnNmeaMessageIgnored( byte[] bytes, int index, int count ) {
            String sentence = new String(bytes, index, count, StandardCharsets.US_ASCII ) ;
            Log.i("NmeaTester","Ignored: " + sentence ) ;
        }
    } ) ;

    // ... Your byte receiving logic...
    boolean keepReceiving = true ;
    while ( keepReceiving ) {
        byte [] bytesReceived = /* receive some bytes from socket, file, whatever... */

        // ... Feed the bytes into the NMEA receiver
        nmeaReceiver.Receive( bytesReceived ) ;
    }

The above code will invoke the appropriate callbacks each time a NMEA sentence is received.