Bug with gps data

[rizla3066]

Hello can someone help me with a problem i have with gps data. I am using an app on my iphone called GPS 2 IP to push NMEA data to my laptop using com0com and netcat. Everything appears to be working, i am getting data through netcat and i have the coordinates in inssider.

This is where my problems begin, the longitude is wrong. Weather it is displayed wrong in inssider or transmitted wrong from GPS 2 IP i do not know. I am in the uk with the following coords

+53.475
-2.282

The gps data from netcat is as follows

User@User-NetBook ~
$ nc 92.40.232.150 11123 | tee /dev/ttyS0
GPS 2 IP Server started. "exit" to finish.
$GPGGA,163859,5328.524,N,216.897,W,1,8,0.9,30.3,M,46.9,M,,*56
$GPRMC,163859,A,5328.524,N,216.897,W,,,280212,003.1,W*73
$GPGGA,163911,5328.522,N,216.899,W,1,8,0.9,30.5,M,46.9,M,,*55
$GPRMC,163911,A,5328.522,N,216.899,W,,,280212,003.1,W*76
$GPGGA,163939,5328.521,N,216.901,W,1,8,0.9,30.6,M,46.9,M,,*5F
$GPRMC,163939,A,5328.521,N,216.901,W,,,280212,003.1,W*7F

it appears correct and i have spoke to the developer who seems to this the data is correct, however the data populated in inssider is wrong -2.16 shows as -216




Now after i bit more testing, i used google earth ad the gps settings in that and the gps data is displayed correctly so i am leaning towards the idea that inssider is at fault.

can someone look at this and comfirm its a bug or my misunderstanding, Thanks

[rizla3066]

Well i have just tried vistumbler and that also gives me the correct location data so it appears inssider is at fault here.

some feedback would be nice

[Tyler]

I have found what causes this problem, and I'm now looking into how to fix it.

[Stephen]

Tyler,

Thanks for jumping on this. If you would like to share a rundown of the solution when you get it for our developers out there, that would be awesome!

[Tyler]

Ok, well, the problem was that the NMEA sentence parser was assuming that the longitude value from the GPGGA and GPRMC sentences were going to have a whole-number part that was 5 characters long. rizla's GPS gives values without any left 0 padding, which inSSIDer's parser didn't account for.

I fixed the problem by left-padding the values with 0s (if needed) before parsing.

[rizla3066]

thanks for the update, do you know if and when a new version is due with the said bugfix?

[mayim]

.... I fixed the problem by left-padding the values with 0s (if needed) before parsing.

Hi Tyler,

I looked at your fork on github but could not see it

hope to see it soon ...

cheers