GPS ToolKit.NET Basics

With GPS ToolKit.NET, it is simple to get GPS position, speed, and direction data. Once you have confirmed that GPS ToolKit can "see" the GPS by using one of the included sample applications, we can begin communicating. For the following examples, you may want to ensure that the GPS has an active satellite lock or is in "demo" mode.

Getting the current position directly

The current position is reported through the GPSToolKit.Position property. This property returns a Position object which contains the latitude, longitude, and altitude, if available, of the current fix. For example:

[Visual Basic]

Imports SciCom.GPSToolKit
[...]
myGPSToolKit.AutoDetectGPS()

' Give GPS ToolKit time to receive first set of position data
System.Threading.Thread.Sleep(2000)

' Get current lat/lon in degrees
Dim pos As Position
Dim lat, lon as Double

pos = myGPSToolKit.Position

If pos.IsValid = True Then
   lat = pos.Latitude.ValueInDegrees
   lon = pos.Longitude.ValueInDegrees
End If


[C#]
using SciCom.GPSToolKit;
[...]
myGPSToolKit.AutoDetectGPS();

// Give GPS ToolKit time to receive first set of position data
System.Threading.Thread.Sleep(2000);

// Get current lat/lon in degrees
double lat, lon;

Position pos = myGPSToolKit.Position;

if(pos.IsValid == true)
{
   lat = pos.Latitude.ValueInDegrees;
   lon = pos.Longitude.ValueInDegrees;
}


[C++]
using namespace SciCom::GPSToolKit;
[...]
myGPSToolKit->AutoDetectGPS();

// Give GPS ToolKit time to receive first set of position data
System::Threading::Thread::Sleep(2000);

// Get current lat/lon in degrees
double lat, lon;

Position *pos = myGPSToolKit->Position;

if(pos->IsValid == true)
{
   lat = pos->Latitude->ValueInDegrees;
   lon = pos->Longitude->ValueInDegrees;
}

In practice, this method is not very useful because it only reads the position once. A more useful implementation would use a loop to read the data every few seconds and perform some processing with each new point. Managing this loop can be cumbersome, however, since it causes high CPU usage and will lock up the application's UI unless special care is taken.

Getting position updates through events

A better method to continuously read GPS position is to handle the PositionUpdate event, which is fired every time GPS position data is updated. By providing a handler function for this event, GPS ToolKit will call the function everytime position data is updated, eliminating the need to continuously poll for new data:

[Visual Basic]

Imports SciCom.GPSToolKit
[...]

Private Sub myGPSToolKit_PositionUpdate(ByVal sender As Object, ByVal e As SciCom.GPSToolKit.PositionUpdateEventArgs) Handles myGPSToolKit.PositionUpdate
    Dim pos As Position
    Dim lat, lon As Double

    pos = e.Position

    If pos.IsValid = True Then
        lat = pos.Latitude.ValueInDegrees
        lon = pos.Longitude.ValueInDegrees
    End If
End Sub


[C#]
using SciCom.GPSToolKit;
[...]

private void myGPSToolKit_PositionUpdate(object sender, SciCom.GPSToolKit.PositionUpdateEventArgs e)
{
    // Get current lat/lon in degrees
    double lat, lon;

    Position pos = e.Position;

    if(pos.IsValid == true)
    {
        lat = pos.Latitude.ValueInDegrees;
        lon = pos.Longitude.ValueInDegrees;
    }
}


[C++]
using namespace SciCom::GPSToolKit;
[...]

private: System::Void myGPSToolKit_PositionUpdate(System::Object *  sender, SciCom::GPSToolKit::PositionUpdateEventArgs *  e)
{
    // Get current lat/lon in degrees
    double lat, lon;

    Position *pos = myGPSToolKit->Position;

    if(pos->IsValid == true)
    {
        lat = pos->Latitude->ValueInDegrees;
        lon = pos->Longitude->ValueInDegrees;
    }
}

Getting speed, direction, or other data can be done in a similar manner. To view a working example of the above methods, please see the Simple GPS sample application.

See Also