OpenNETCF SDF - GPS Example?

  • Thread starter Thread starter Hilton
  • Start date Start date
H

Hilton

Hi,

I downloaded OpenNETCF SDF 1.3. The GPSSample code does not compile on it -
perhaps I got an incorrect version. I'm a decent C# coder, but I'm havng a
helluva time with no success. Here are the issues:

1. GPS Sample does not compile - status changed to state etc... I finally
got it to compile.
2. When I quit the EXE, it doesn't die even after "Running Programs" +
"Stop"
3. Tap on Start, nothing happens
4. Wrote my own code to use the GPS class - got nowhere.
5. API is not documented

All I need is some C# code that uses the GPS class (or any other class) that
can report back some sattelite information and the lat/long. I can take it
from there.

I would really appreciate some help getting the SDF to work properly. I was
kinda expecting it to work 'out the box' and I'm pulling my hair out. FWIW:
Axim X30+BT with Dell BT GPS.

A few other questions, is "COM8:" and 4800 the standard settings for all BT
GPS? Will 9600 or 19200 work? Is "COM8:" hard-coded?

Many many many thanks in advance,

Hilton
 
I've updated the Pocket PC GPS Sample (working on Smartphone now) in Vault.
It now compiles with the SDF code in vault (it was a change of only about 4
lines of code to match some naming changes I made to remove hungarian
notation in class names).

Get the SDF code, get the ssample code and rebuild. I don't have a device
to test with, so that's the best I can offer att his point.

-Chris
 
Chris,
I've updated the Pocket PC GPS Sample (working on Smartphone now) in Vault.
It now compiles with the SDF code in vault (it was a change of only about 4
lines of code to match some naming changes I made to remove hungarian
notation in class names).

Get the SDF code, get the ssample code and rebuild. I don't have a device
to test with, so that's the best I can offer att his point.
Click to expand...

Thanks Chris. Using the GPSSample code, I wrote my own layer and it is now
working great - thanks OpenNETCF!!!

However... Today I took it up in a small plane. There were 9 satellites in
view, it had a 3D fix, most of the numbers looked right, except altitude.
It read pretty close on the ground (I understand the small diff here -
that's not the problem). I then climbed to 5000' at which point the
Altitude call returned about 1400 or so - way wrong. My friend had a Garmin
with him - his GPS altitude read within a few feet of our altimeter reading
of 5000'.

Is this a known problem? Any ideas?

Thanks,

Hilton
 
No idea (again, I don't have a device, nor a plane to test). Can you modify
the code top capture the raw GPS output and the corresponding altitude
returned by the SDF code at the same time? Dump it to a log file to see if
what's going in and what's coming out correspond. Also 1400m is
apprxomiately 4600 feet, so could we be looking at a conversion failure?

-Chris
 
Chris,
No idea (again, I don't have a device, nor a plane to test). Can you modify
the code top capture the raw GPS output and the corresponding altitude
returned by the SDF code at the same time? Dump it to a log file to see if
what's going in and what's coming out correspond. Also 1400m is
apprxomiately 4600 feet, so could we be looking at a conversion failure?
Click to expand...

You da man! I hadn't thought of that, but thinking back on the flight, the
GPS always seemed to be reading about 1/3 of the actual value. I took a
peek at the code, and the one line of code is commented with:

"Altitude in meters according to WGS-84 ellipsoid"

I'll multiply by 3.2808399 to get feet - THANKS!!!

Hilton
 
Hilton,

a GGA sentence which contains altitude is always in metres.

In my code gga[9] in the gga sentence contains the altitude. I would presume
the OpenNetCF code would also use Split to break up the sentence.

Check the following as an example

GGA - Global Positioning System Fix Data
GGA,123519,4807.038,N,01131.324,E,1,08,0.9,545.4,M,46.9,M, , *42
123519 Fix taken at 12:35:19 UTC
4807.038,N Latitude 48 deg 07.038' N
01131.324,E Longitude 11 deg 31.324' E
1 Fix quality: 0 = invalid
1 = GPS fix
2 = DGPS fix
08 Number of satellites being tracked
0.9 Horizontal dilution of position
545.4,M Altitude, Metres, above mean sea level
46.9,M Height of geoid (mean sea level) above WGS84
ellipsoid
(empty field) time in seconds since last DGPS update
(empty field) DGPS station ID number

$GPGGA,063042.801,3750.7158,S,14505.3629,E,1,04,3.1,83.1,M,,,,0000*25

Graham
 
Graham said:
Hilton,

a GGA sentence which contains altitude is always in metres.

In my code gga[9] in the gga sentence contains the altitude. I would presume
the OpenNetCF code would also use Split to break up the sentence.

Check the following as an example

GGA - Global Positioning System Fix Data
GGA,123519,4807.038,N,01131.324,E,1,08,0.9,545.4,M,46.9,M, , *42
123519 Fix taken at 12:35:19 UTC
4807.038,N Latitude 48 deg 07.038' N
01131.324,E Longitude 11 deg 31.324' E
1 Fix quality: 0 = invalid
1 = GPS fix
2 = DGPS fix
08 Number of satellites being tracked
0.9 Horizontal dilution of position
545.4,M Altitude, Metres, above mean sea level
46.9,M Height of geoid (mean sea level) above WGS84
ellipsoid
(empty field) time in seconds since last DGPS update
(empty field) DGPS station ID number

$GPGGA,063042.801,3750.7158,S,14505.3629,E,1,04,3.1,83.1,M,,,,0000*25
Click to expand...

Wow - it has Height above sea-level??? I thought it only had height above
WGS84. Now i'm going to go see what 'altitude' I get from the SDF. Thanks
for this post!

Hilton
 
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