Re: [gpsd-dev] Need p/d help with gpsd and or gps HW - no response after gps polling

[Gary E. Miller]

Yo Steve!

On Tue, 12 Jul 2016 22:47:19 -0500
Steve Lang <address@hidden> wrote:

> HW Config: Pi 3, Adafruit GPS hat, and LNA
> SW Config: latest Jessi / clockmaker install script abd SW updates to
> support installing the following scons options:

OK.  What kernel version?  What did you do to get systemd out of the way?
I suspect that is your problem.  Systemd has been sabotaging many people.

I have the same config, except I use Gentoo stable and kernel
4.4.14-v7+.  No problems for me.  You can see how it works well here:

    https://pi3.rellim.com/week/

> scons timeservice=yes nmea0183=yes fixed_port_speed=9600
> fixed_stop_bits=1 xgps=yes leapfetch=yes qt=yes gpsdclients=yes

The Adafruit is a mediatek chip, so you should also enable the 
"mtk3301" support.

> Symptoms: gpsd appears to hang if gpsd does not receive data

That is the design of gpsd.  Nothing in means nothing out.

B why would you ever not have data in?

> When the problem happens, ntp moves off the gps shm source to an
> external provider and the following is logged:

That all looks good.

> The last 4 lines are repeated for the remainder of the log file.

Yeah, you still have PPS, but no serial data.

> ----------Cut------------
> gpsd:DATA: /dev/gpsd0 returned zero bytes
> gpsd:DATA: /dev/gpsd0 will be repolled in 0.010000 seconds
> ---------Cut-------------

Yup, no serial data.  No data in, thus no data out.  As designed.

> Due to lack of logging in this path I cant tell where we ended up and
> if an attempt was planned to resume IO to this GPS.

Nothing to log.  No data in, thus no data out.

> I ran gpsmon when this condition is happening.which seems to return
> valid data ..

Forget gpsmon, it will just confuse the issue.  Use cgps.  If gpsd is
disconnected then gpsmon may directly connect to the GPS and mislead you
into thinking gpsd is fine.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

pgphmKURMCNC_.pgp
Description: OpenPGP digital signature