NmeaLocationDataSource Class

Member Function Documentation

NmeaLocationDataSource::NmeaLocationDataSource(const Esri::ArcGISRuntime::SpatialReference &receiverSpatialReference, const Esri::ArcGISRuntime::SpatialReference &outputSpatialReference, Esri::ArcGISRuntime::DatumTransformation *outputDatumTransformation, QObject *parent = nullptr)

Creates an NMEA data source object.

• receiverSpatialReference - The SpatialReference of incoming NMEA receiver data.
• outputSpatialReference - The SpatialReference to project the NmeaLocation to.
• outputDatumTransformation - The DatumTransformation to use to project the NmeaLocation.
• parent - The optional parent QObject.

Locations created from an NMEA data source object instantiated with this constructor will be projected from the SpatialReference defined by the receiverSpatialReference parameter to the SpatialReference defined by the outputSpatialReference parameter using the outputDatumTransformation. If the outputSpatialReference parameter is nullptr , the locations will not be projected and the locations will be in the receiverSpatialReference; if the outputDatumTransformation parameter is set it will be ignored. This constructor can be used when a receiver is outputting locations in a SpatialReference other than WGS84, such as when using a reference base station, and/or the application requires the output locations to be projected to a different SpatialReference using a DatumTransformation.

NmeaLocationDataSource::NmeaLocationDataSource(const Esri::ArcGISRuntime::SpatialReference &receiverSpatialReference, const Esri::ArcGISRuntime::SpatialReference &outputSpatialReference, QObject *parent = nullptr)

Creates an NMEA data source object.

• receiverSpatialReference - The SpatialReference of incoming NMEA receiver data.
• outputSpatialReference - The SpatialReference to project the NmeaLocation to.
• parent - The optional parent QObject.

Locations created from an NMEA data source object instantiated with this constructor will be projected from the SpatialReference defined by the receiverSpatialReference parameter to the SpatialReference defined by the outputSpatialReference parameter. If the outputSpatialReference parameter is empty, the locations will not be projected and the locations will be in the receiverSpatialReference. This constructor can be used when a receiver is outputting locations in a SpatialReference other than WGS84, such as when using a reference base station, and/or the application requires the output locations to be projected to a different SpatialReference.

NmeaLocationDataSource::NmeaLocationDataSource(const Esri::ArcGISRuntime::SpatialReference &receiverSpatialReference, QObject *parent = nullptr)

Creates an NMEA data source object.

• receiverSpatialReference - The SpatialReference of incoming NMEA receiver data.
• parent - The optional parent QObject.

Locations created from an NMEA data source object instantiated with this constructor will have a SpatialReference defined by the receiverSpatialReference parameter. This constructor can be used when a receiver is outputting locations in a SpatialReference other than WGS84, such as when using a reference base station.

NmeaLocationDataSource::NmeaLocationDataSource(QObject *parent = nullptr)

Creates an NMEA data source object.

• parent - The optional parent QObject.

Locations created from an NMEA data source object instantiated with this constructor will have a SpatialReference of WGS84.

[override virtual protected slot] void NmeaLocationDataSource::onStart()

Reimplements: AbstractLocationDataSource::onStart().

Reacts to start requests by starting the location data source.

Note: You should not call this method directly - use start instead.

[override virtual protected slot] void NmeaLocationDataSource::onStop()

Reimplements: AbstractLocationDataSource::onStop().

Reacts to stop requests by stopping the location data source.

Note: You should not call this method directly - use stop instead.

[override virtual] NmeaLocationDataSource::~NmeaLocationDataSource()

Destructor.

Esri::ArcGISRuntime::DatumTransformation *NmeaLocationDataSource::outputDatumTransformation() const

Returns the DatumTransformation to be used in the project operation.

If set, this property will be used as the DatumTransformation in the call to GeometryEngine::project. For this property to be used, the outputSpatialReference also must be set.

Esri::ArcGISRuntime::SpatialReference NmeaLocationDataSource::outputSpatialReference() const

Returns the GeometryEngine::project method to generate the output spatial reference.

The projected point will be stored in NmeaLocation::position. If this property is nullptr , the NmeaLocation::position will be contain the original incoming x,y,z values from the NMEA data sentence and the receiverSpatialReference.

void NmeaLocationDataSource::pushData(const QByteArray &data)

Reads the input NMEA data, with which it creates a NmeaLocation.

• data - The data buffer that contains NMEA data.

When pushing data

• Each sentence needs to begins with a '$'
• Each sentence needs to end with carriage return/line feed sequence
• Single or multiple sentences can be pushed at one time. All strings in the buffer will be parsed
• There is no explicit limit on the amount of data that can pushed at one time
• If partial sentences are pushed the data source accumulates (and concatenates) the pushed data until a carriage return/line feed sequence is reached
• The data source parses these messages types: GGA, GSA, GST, GSV, RMC, VTG
• Each sentence's checksum is validated
• Unknown/bad/incorrect sentences are ignored (they do not produce any location, satellite updates etc.)
• Sentences support up to 256 characters (this is beyond the NMEA spec's 82 character limit to support receiver's that output longer sentences)
• Messages should be of the form: "$XXYYY,[data]*[checksum]\r\n"

Example: $GPGGA, 092750.000, 5321.6802,N, 00630.3372,W, 1, 8, 1.03, 61.7,M, 55.2,M,,*76 $GPGSA,A, 3, 10, 07, 05, 02, 29, 04, 08, 13,,,,, 1.72, 1.03,1.38*0A $GPGSV, 3, 1, 11, 10, 63, 137, 17, 07, 61, 098, 15, 05, 59, 290, 20, 08, 54, 157,30*70 see https://www.nmea.org/ for more information on the NMEA standard. The QByteArray can be obtained by, for example, converting from a QString; or by connecting to a GPS device, (either via QBluetoothSocket or QSerialPort) using QIODevice::read(qint64 maxSize).

Esri::ArcGISRuntime::SpatialReference NmeaLocationDataSource::receiverSpatialReference() const

Returns the SpatialReference to be assigned to the output NmeaLocation, the default is WGS84

By default this will be WGS84 for its horizontal (WKID=4326) and vertical reference systems (WKID=115700), this can be set to a different SpatialReference if a receiver returns locations in a different reference system.