Re: gpsd-users Digest, Vol 104, Issue 5

[Gary E. Miller]

Yo Bradley!

On Tue, 8 Sep 2020 09:08:06 -0400
Bradley McFadden <bmcfadden@laurentian.ca> wrote:

> > You just said cat read nothing.  And now cat read something?  
> 
> Sorry about the confusion. Yes, cat does read /dev/ttyXTRX0. It
> produces this output, which is what I expect:
> 
> root@gr110:/home/sail# stty -F /dev/ttyXTRX0 speed 9600 && cat
> /dev/ttyXTRX0 9600
> �$PMTK011,MTKGPS*08
> $PMTK010,001*2E
> $PMTK011,MTKGPS*08
> $PMTK010,002*2D
> $PMTK011,MTKGPS$PMTK001,10,1*03
> $PMTK011,MTKGPS$PMTK001,10,1*03
> $GNGGA,235942.870,,,,,0,0,,,M,,M,,*52
> $GPGSA,A,1,,,,,,,,,,,,,,,*1E
> $GLGSA,A,1,,,,,,,,,,,,,,,*02
> $GPGSV,1,1,00*79
> $GLGSV,1,1,00*65
> $GNRMC,235942.870,V,,,,,0.00,0.00,050180,,,N*5B

That shows no fix and no time.   So not very useful for PVT.

> > And what does this show:
> >      netstat -apn | fgrep 2974  
> 
> This command produces no output.

Now neither systemd not gpsd is running.

> > Something wrong with your system as that did not work.
> > What distro is this again?
> > Until "lsof /dev/ttyXRX0" works, no point trying gpsd.  
> 
> The computer is running Ubuntu 20.04.1 LTS.
> I looked into the warning and "lsof" supposedly produces the warning
> because no user except the user that mounted
> a FUSE filesystem can enter it. Using the -e argument of lsof, the
> warning disappears and the command produces
> no output:

Whcih says that no program hass /dev/ttyXRX0 open.

> Original Command:
> root@gr110:/home/sail# lsof /dev/ttyXTRX0
> lsof: WARNING: can't stat() fuse file system /run/user/1000/doc
>       Output information may be incomplete.
> 
> Updated Command:
> root@gr110:/home/sail# lsof -e /run/user/1000/doc /dev/ttyXTRX0

Mostly what you did is tell lsof to ignore the error.  So the error
still exists.  Since port 2947 is now free, and you can cat the
device it is likely not in uses.  So the lsof has no intruding program
to find.

> > Which, of course, is expalined in the gpsd doc on systemd(reck).  
> 
> I have not read this. I was unable to find it after some googling.
> Could you point me in the right direction?

Right there in the gpsd web site:

https://gpsd.io/troubleshooting.html#systemdtroubleshooting

But since port 2947 is now unused on your system, systemd(umber) is not
involved now.  IMHO that is a good thing, try running gpsd from the CLI
now.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  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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