Cant get a location Fix from GNSS


#1

I am trying to get a GPS-Position from the WP8548, and it keeps failing.
I have followed the TexLoc example, and also attempted to do it via the cmd-line as well as using the le_gnss functions. It just keeps failing to get a fix. When i Inspect the /dev/nmea strings, i can see that it has 11 GLONASS satellites in view, and 16 GPS satellites in view, yet all that the xxGSA gives is “GPGSA,A,1,*1E” & “GNGSA,A,1,*00”, and also this “GPGGA,083646.6,0,*71” & “GNGNS,083646.6,NNN,*0A”. As I understand it, it only needs to see 3 satelites to be able to get a fix, so what could I be doing wrong?

Thanks


#2

Can you please use the command:
echo ‘$GPS_START’ > /dev/nmea
And then:
cat /dev/nmea
and check the output.

Also, parallely you can monitor the various thing by the commnad in new terminal:

AT!GPSSATINFO?
AT!GPSSTATUS?
AT!GPSLOC?

Please share the result.


#3

After starting the gnss, I got the following from cat /dev/nmea:

$PQXFI,56
$GPRMC,V,N
53
$GPGSV,3,1,09,32,33,043,33,01,02,03,*44
$GPGSV,3,2,09,04,11,12,02,137,13,16,220,*74
$GPGSV,3,3,09,14,61,056,41
$GPVTG,T,M,N,K,N
2C
$GPGSA,A,1,*1E
$GPGGA,0,*66

And at the same time, on the /dev/ttyAT:

AT!GPSSATINFO?

Satellites in view: 1 (2016 11 29 1 07:18:45)

  • SV: 32 ELEV: 34 AZI: 43 SNR: 21

OK

AT!GPSSTATUS?

Current time: 2016 11 29 1 07:19:00

2016 11 29 1 07:19:00 Last Fix Status = NONE
2016 11 29 1 07:17:34 Fix Session Status = ACTIVE

No TTFF available

OK

AT!GPSLOC?

Not Available

OK


#4

After running it for a couple of minutes, the /dev/ttyAT responces changed to :

AT!GPSSATINFO?

Satellites in view: 5 (2016 11 29 1 08:37:26)

  • SV: 14 ELEV: 28 AZI: 28 SNR: 23
  • SV: 31 ELEV: 37 AZI: 99 SNR: 16
  • SV: 32 ELEV: 2 AZI: 29 SNR: 33
  • SV: 66 ELEV: 0 AZI: 0 SNR: 27
  • SV: 87 ELEV: 42 AZI: 78 SNR: 21

OK

AT!GPSSTATUS?

Current time: 2016 11 29 1 08:38:40

2016 11 29 1 08:35:44 Last Fix Status = FAIL, FAILCODE = 12
2016 11 29 1 08:35:45 Fix Session Status = ACTIVE

No TTFF available

OK


#5

I hab the same problem


#6

I had found that changing the GNSS antenna connection, to an Active Antenna type (3V on Antenna line, with a capacitive connection to Module) got it fixed. Hope this helps you bengme00.