GPS Problems

[tdunlavy]

I followed this tutorial: http://makezine.com/projects/make-37/gps-cat-tracker-2/

Both the hardware and the code are functional however I'm not getting the results expected.

The GPS.txt file on the SD card only contains time/date and no coordinates. Attempts to import any of the information to Google Earth fail.

I've left the device running the GPS code outside high in the air for ~1 hour and I get the same results.

Help would be greatly appreciated.

Example of some of the data:

Code: [Select]

$PSRF150,1*3E
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N$PSRF150,1*3E
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71
$GPRMC,,V,,,,,,,,,,N*53
$GPGGA,,,,,,0,00,,,M,0.0,M,,0000*48
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,01,00,000,,02,00,000,,03,00,000,,04,00,000,*7C
$GPGSV,3,2,12,05,00,000,,06,00,000,,07,00,000,,08,00,000,*77
$GPGSV,3,3,12,09,00,000,,10,00,000,,11,00,000,,12,00,000,*71

[bryceb04]

I just built this yesterday, so I had a similar experience.

An hour should be sufficient for a completely cold start, but it could take longer depending on conditions. It looks like the data you're logging indicates it is working, but appears to not be seeing the satellites. Beyond that bit of stuff you already knew, I haven't dug into NMEA code enough to troubleshoot more. Especially after mine started working correctly...

As for bringing it into Google Earth, you've got to find a way to convert the NMEA to KML. Google Earth failed at this, but GPSBabel worked for me.

Edit: My GPS shield chip is the Telit SE868 V2. Appears to be 32 channel, GPS+GLONASS. Differs from the one on the GPS shield ordering page (Telit JF2), but definitely an upgrade. Could explain why my fix came faster.