New GPSDriver library

[Erel]

The GPSDriver uses Microsoft GPS Intermediate Driver to receive GPS data.
This library can work with both internal and external GPS devices.
Using this library is simpler than with the GPS library as there is no need to manually connect to a serial port.
This library should be added to both the desktop and the device, however the functionality is not available on the desktop.
Requirements are Windows Mobile 5.0 or newer devices installed with .Net Compact Framework 2.0.

I want to thank Agraham for writing the first version of this library.

Setup instructions:
- Unzip the attached file.
- Copy GPSDriver.cs, GPSDriver.dll and GPSDriver.chm to Basic4ppc libraries folder:
C:\Program Files\Anywhere Software\Basic4ppc Desktop\Libraries

Edit: V1.11 is attached. This version fixes a bug in the GPSConverter object related to conversions of negative longitude coordinates.

An example is also included in the zip file.
The online manual is available here: GPSDriver

See this post about external GPS devices: http://www.basic4ppc.com/forum/offic...html#post18443

[agraham]

GPSDriver.chm doesn't work on my machines, either Vista or XP. I just get "The address is not valid" errors Any ideas?

[klaus]

On my XP machine it works !?

[agraham]

Found it! - A security issue I've not come across before I keep the settings on my machines quite tight.

Right-click the CHM file, and then click Properties.
Click Unblock.
Double-click the .chm file to open the file.

If anyone with Vista has this problem note that you can't unblock it while it is in the "Libraries" folder owing to Vista security. You will need to copy it to a folder outside "Program Files", unblock it, delete the one in "Libraries" and copy the unblocked one back. At least that's what I had to do!

[agraham]

A bug EllipsoidAltitude is checking the wrong flag for validity

public float EllipsoidAltitude
{ get { return SeaLevelAltitudeValid ? gpsdata.flAltitudeWRTEllipsoid : InvalidData; } }

And a comment.

There is inconsistent naming of "SatellitesInViewCount which is plural and SatelliteInUseCount which is singular.

[Mr_Gee]

Hi Erel, this is great news!!
thanks for this new lib (and you too Agraham )

Just tried your demo application, when I run it and click connect i get an error

An error occurred on sub main.displaygps

Line number : 53

If Satellites.shouldCalculate Then Satellites.UpdateSatellites

Error description
Format exception
Continue?

If I click yes then the error pops up again, but If I click yes and click on satellites (menu item) quickly the table shows and gets updated
when I close the satellites form works like it should...

[Erel]

Thank you guys. I've updated the library to version 1.01 with a fix to the validity check.
The demo program was updated and now Satellite.shouldCalculate is first initialized to false as required.

[taximania]

I will try this whilst at work tomorrow, and post my findings later on

[derez]

Erel and Agraham
thanbks for this library, I'm already running my navigation program and it works nicely. The satellites code becomes very easy with the new structured array which includes the "Used".

Still I'm not sure that EllipsoidAltitude is doing what it should - I get the same altitude all the time (usually there are variations of few meters as the gps stabilizes).

Please explain the difference between the two types of altitudes. all altitude calculations are with reference to a specific Geoid which is defined by each country or for an area, or by using the general WGS84.(see attached list)
What does "sealevel" use ?

[agraham]

Originally Posted by derez

Still I'm not sure that EllipsoidAltitude is doing what it should - I get the same altitude all the time (usually there are variations of few meters as the gps stabilizes).

As long as you have version 1.01 then Ellipsoid altitude does what I expect on my Diamond. It appears to return (correctly) the present altitude above the WGS84 ellipsoid which when corrected using the transformation equations and parameters specified by our national mapping agency (the Ordnance Survey) give a good match to my latitude, longitude and altitude on our national standard geoid (OSGB36/ODN) on which our UK maps are drawn.

I don't have the detailed knowledge to answer the rest of your query as I have only researched the WGS84 to UK standard transformation using the equation and data supplied by our Ordnance Survey.