Re: [gpsd-users] ublox EVK-6 problem

[Marek Floriańczyk]

Dnia sobota, 22 kwietnia 2017 13:07:05 CEST Gary E. Miller pisze:
> Yo Marek!
> 
> On Sat, 22 Apr 2017 14:42:23 +0200
> 
> Marek Floriańczyk <address@hidden> wrote:
> > Gpsd is from Debian Stretch 64bit, version 3.16-4 and it runs with -N
> > parameter. I haven't modified anything in config.
> 
> Can you tell us all the options used to start gpsd?  And verify you
> have the -n parameter in use.

Hi,

Gpsd is started with -N option.
ps ax|grep gpsd
 5949 ?        S<s    0:00 /usr/sbin/gpsd -N

EVK-6H is connected through USB and it seems that /dev/ttyACM0 is created for 
it.

I have made additional tests. 
With one app (server) connected to gpsd I was driving with my gps and laptop 
for over an hour and no problem, until I had to put my app (server) into debug 
mode (under GDB) - then it hangs again.
I have checked with gpsmon during that and it was giving right data, well at 
least coordinates were changing.
So it looks like a plugin problem.

In the source code of this plugin I can see functions to read GSV:
/*
    $GPGSV,2,1,08,01,40,083,46,02,17,308,41,12,07,344,39,14,22,228,45*75
    Where:
    
      GSV          Satellites in view
      2            Number of sentences for full data
      1            sentence 1 of 2
      08           Number of satellites in view
      
      01           Satellite PRN number
      40           Elevation, degrees
      083          Azimuth, degrees
      46           SNR - higher is better
         for up to 4 satellites per sentence
      *75          the checksum data, always begins with *
  */

Function to read GSA
/*
    $GPGSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39

    Where:
      GSA      Satellite status
      A        Auto selection of 2D or 3D fix (M = manual) 
      3        3D fix - values include: 1 = no fix
                                        2 = 2D fix
                                        3 = 3D fix
      04,05... PRNs of satellites used for fix (space for 12) 
      2.5      PDOP (dilution of precision) 
      1.3      Horizontal dilution of precision (HDOP) 
      2.1      Vertical dilution of precision (VDOP)
      *39      the checksum data, always begins with *
  */

But can't find GGA - where latitude and longitude should be read.
Does it mean that Qt itself is parsing that string, not the plugin ?

I know that these question may be out of the scope of this list.

Does someone recommend a different way to get latitude/longitude from gpsd ? 
Like telnet to port and parse GGA sentence ?

Best Regards
Marek

> 
> Easy way to see how gpsd is started:
> 
> $ pstree -paul | fgrep gpsd
> 
>   |-gpsd,25354,nobody -n /dev/ttyS0
>   |
>   |   `-{gpsd},25368
> 
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
>       address@hidden  Tel:+1 541 382 8588
> 
>           Veritas liberabit vos. -- Quid est veritas?
>     "If you can’t measure it, you can’t improve it." - Lord Kelvin