GetHeading

Description

Populates a GPSHeading structure with data from the current heading.

Applies to

GPS and SerialGPS objects

Syntax

Integer GPSname.GetHeading( GPSHeading )

Argument	Description
GPSname	Name of the GPS or SerialGPS object
GPSHeading	Structure passed by reference that stores speed and directional information used by the SerialGPS object

Returns

Integer. Returns 1 for success and 100 or a negative number for an error. The following is a list of possible error codes and their meanings:

100 End of buffer. The requested data was not found.
-1 General error.
-10 Invalid object. Could occur if the GPS object instance is corrupted.
-13 Not previously opened. This function cannot be called until a GPS object or SerialGPS object has been successfully opened.
-14 Read timeout. Occurs when the timeout interval (a ConfigParams property of the SerialGPS object) is exceeded.
-15 Read Failure. Unable to read the file or serial port.
-16 Parser Error. Parser is unable to interpret a sentence. This error is generated when nonstandard tokens are discovered while parsing the GPS data.
-17 Checksum Error. Most GPS sentences end in a two-digit checksum value. The PocketBuilder parser verifies this value and reports a checksum error if the calculated value does not match the stated value.

Usage

Use this function to populate a GPSHeading structure with information about the direction of travel, ground speed, and magnetic variation.

Examples

Example 1

The following lines create a SerialGPS object, retrieve information about the current position fix, test the validity of the GPSHeading object, and write data to a multiline edit box:

SerialGps myGPS
real TrueHeading, Speed, MV
char MVD
GPSHeading myGPSHeading

Integer rc

MyGPS = CREATE SerialGPS
myGPS.Open()
...

rc = MyGPS.GetHeading(myGPSHeading)
IF rc = 1 THEN

TrueHeading = myGPSHeading.Heading
Speed = myGPSHeading.groundspeed
MV = myGPSHeading.MagneticVariation
MVD = myGPSHeading.MagneticVariationDirection
mle_1 = "Ground speed: " + String(Speed)
mle_1 += "True heading: " + String(TrueHeading) + "~r~n"
mle_1 += "Variation: " + String(MV) + MVD

ELSE

//Process error

END IF