Re: [gpsd-users] cgps/xgps NO FIX but gpsmon works?

[Gary E. Miller]

Yo Noeneel!

On Thu, 11 Jul 2019 09:47:49 +0000
Noeneel Sharma <address@hidden> wrote:

> New to the world of GPS and trying to get my BT-Q1000x to work with a
> Raspberry Pi.

Who makes that?  Qstarz?  never heard of them.

> I’ve trawled through the new and tried all the
> suggestions but still can’t get passed the issue of NO Fix showing
> with CGPS and XGPS.

I assume you are outdoors, and the GPS warmed up over 30 minutes, etc?

> It all works fine with GPSMON. I’ve even compiled
> and tried v3.19 with no luck, although CGPS still shows as 3.17 (what
> installed on the Pi originally by me via apt install).

You can not mix and match gpsd client/server versions.  You will get
strange errors.  You need to completely remove any distro installed
gpsd companents.

> pi@raspberrypi:~/source/gpsd-3.19 $ stty -F /dev/ttyACM0 9600

So a GPS on USB?  Not bluetooth?

> pi@raspberrypi:~/source/gpsd-3.19 $ cat /dev/ttyACM0
 
> .804,06,01,1980,,*50

Partial sentence.

> $GPGGA,019834.804,2797.1799,S,95302.5931,E8

Missing checksum.

> $GPZDA,019855.804,06,01,1980,,*50
                    ^^^^^^^^^^
Uh, oh.  Unless you have a time machine, the date is not January 1,
1980.  That is very broken.

> $GPGGA,019856.804,2797.1799,S,95302.5931,E,0,0,,201.1,M,37.2,M,,*55
> $GPGSA,A,1,,,,,,,,,,,,,,,*1E

Looks OK.

> pi@raspberrypi:~/source/gpsd-3.19 $ sudo gpsd /dev/ttyACM0 -n -N -D3
> -F /var/run/gpsd.sock

Why are you using both a device AND a socket?

Also: sudo is bad for your mental health.

> gpsd:INFO: launching (Version 3.19)
> 
> gpsd:INFO: listening on port gpsd
> 
> gpsd:ERROR: shmget(0x47505344, 20808, 0666) for SHM export failed:
> Invalid argument

Not good.  gpsd can not seem to use your SHM interface.  That will 
break gpsd clients.

> gpsd:INFO: KPPS:/dev/ttyACM0 kernel PPS will be used

Except ttyACM

> gpsd:INFO: /dev/ttyACM0 identified as type NMEA0183, 1 sec @ 9600bps

Good.

> gpsd:WARN: ZDA year less than clock year, probable GPS week rollover
> lossage

Bad.  No good date, means the fix is not trusted.  gpsd does not
trust a GPS with a bad date.

If your GPS has sat outside with a good sky view for more than 30
minutes then your GPS is broken.

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

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