New GPSDriver library

[ashrafidkaidek]

Folks,
This is a great library, I tried to use it and it works with no issues, I just have one question:

Assuming that I have established a GPS connection and for some reason I lost that connection later (e.g. driving through a tunnel …etc.) how can I display a message to the user letting him know that the GPS signal got lost.

I have tried to use this code but it did not work, actually nothing happen, it seems even if the GPS signal get lost, then the Latitude, Longitude and other GPS information will still considered to be valid

If gps.Latitude <> gps.InvalidData Then
Else
Show the message here
End If


In the example provided (GPSDriverDemo ) I have noticed this code:
----------------------------------------------------------------------------
If If gps.Opened = True Then
Label1.Text = "gps is open."
Timer1.Interval = 1000
Timer1.Enabled = True
Else
Label1.Text = "gps failed to open."
End If= True Then
----------------------------------------------------

Dose that mean when the device loses the GPS signal then gps.Opened will return false?

Thank you all

[mjcoon]

Originally Posted by ashrafidkaidek

[1] ... it seems even if the GPS signal get lost, then the Latitude, Longitude and other GPS information will still considered to be valid

[2] Does that mean when the device loses the GPS signal then gps.Opened will return false?

[1] I think this will depend on your GPS. Because the GPS signal is rather fragile, and tunnels etc exist, I think it has long been the habit of GPSs to assume that it is best to consider that if the signal vanishes then the output should just extrapolate the motion before it vanished. Usually in a tunnel there is no need for ongoing navigation! Hopefully this extrapolation does not continue indefinitely; how long (in duration) were your tunnels?

[2] Because of my answer to [1], I am sure that this will not be the case.

Mike.

[agraham]

Look at the gelp for GetGPSData. Theoretically if the data is older than the time value you specify in GetGPSData then the data should be returned as InvalidData and GetGPSData should return false. In practice I am not convinced this actually happens owing to a possible bug in the Windows Intermediate Driver that GPSDriver talks to.

[ealvarez]

Hi Erel,

The GPSdriver example is displaying an error on sub _main_mnuconnect_click Can't find Pinvoke DLL gpsapi.dll. The GPSSdriverNMEADemo.exe seems to work but is not showing anything in the textbox. It's connecting properly to com4 and the reading count is going up but when trying to save it brings only an empty file. I'm using a generic PND with CE 5.0. NETCF 2.0 SP2 is installed properly. Do you have any idea what the problem could be?

[agraham]

As it is a CE and not a Windows Mobile device it looks like the manufacturer has chosen not to include the GPS dlls in the device ROM. Windows Mobile devices must conform to a minimum specification to be called Windows Mobile. For CE devices the configuration is not controlled and is up to the manufacturer.