Re: [gpsd-users] configproblem with ntp and pps,

[Gary E. Miller]

Yo address@hidden

On Fri, 22 Dec 2017 20:20:27 +0100
"address@hidden" <address@hidden> wrote:

> Can you please tell what's wrong with my configuration? 

We'll see.

> I have tried many combinations (type 20, 22, 28 for the 127.127.t.u),
> but only the shared memory driver seems to work, a bit.

Well, the shared is how gpsd talks to ntpd, and you are using gpsd.
Many other options not using gpsd, but IMHO gpsd is the way to go.

> I have a ublox Neo8 connected to my raspi. GPS is working:

Good.

> and the pps-signal on gpio 18 seems also to be well:

So this is a RasPi?  Running what distro?  Running distro
copies of gpsd and ntpd, or user insalled copies?

>       $: ppstest /dev/pps0 
>       trying PPS source "/dev/pps0"

Good.

> I'm not able bring ntpd to use my GPS and pps. 

Skipped a couple steps here.

How did you start gpsd?

What does cgps tell you about your GPS data?

What does ntpshmmon tell you about what gpsd is putting in SHM?


> xSHM(0)          .GPS.            1 l  180   16  0  0.000 -105.42 0.000

ntpd is seeing nothing from gpsd.  Maybe no GPS lock, maybe??

> Here's a part of my ntp.conf
>       # GPS Serial data reference (NTP0)
>       # GPS PPS reference (NTP1)

PPS should be first, GPS should be last.  PPS should be 'prefer'

I do this, cleaner syntax:

refclock shm unit 1 maxpoll 4 refid PPS flag4 1 prefer
refclock shm unit 0 maxpoll 4 time1 0.133 refid GPS flag4 1

> $: gpsd -n -N -D3 /dev/ttyAMA0 
> gpsd:INFO: KPPS:/dev/ttyAMA0 RFC2783 path:/dev/pps1, fd is 7

pps1?  I thought your PPS was on pps0??

> gpsd:INFO: KPPS:/dev/ttyAMA0 kernel PPS timeout Interrupted system call
> gpsd:INFO: KPPS:/dev/ttyAMA0 kernel PPS timeout Interrupted

No PPS on /dev/pps1...

gpsd should be using pps0:

This from my RasPi to show I'm using pps0

# lsof /dev/pps0
COMMAND  PID   USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
gpsd    1996 nobody    6u   CHR  252,0      0t0 1149 /dev/pps0

Here is how I start my gpsd on my RasPi:

# gpsd -n /dev/ttyAMA0

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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