Re: [gpsd-users] Is GPSD receiving PPS?

[hans mayer]

hi jon,

maybe i didn't explain exaclty.
i didn't say PPS is wired to the wrong pin.
i said pin 18 is a pin where a 1PPS could be sampled.
i do not know where your adafruit is connected.
but pin 18 is definitely not the pin where you can read
the serial data-stream. for this you need a serial interface.
and as gary said, you need both: 1PPS and serial

btw: last summer i run into the same issue.
i couln't fix the problem even when gary answered all my questions.
finally i gave up.

my solution was:
i compiled gpsd without pps support.
ntpd is using the 1PPS directly. ( 127.127.22.0 device driver )
gpsd provides shared memory with coarse time information
and ntpd is using this via 127.127.28.0 driver. because
beside the 1PPS you need at least one source with time information.
this was quite straight forward than.
i assume you want to setup a stratum 1 server. you never mentioned that.

gary, i know you don't like this solution but
i did't find another one with my hardware / operating system.

at that time i used gpsd 3.15 on an banana pi.
and it's still working fine.


kind regards
hans

--



Am 04.03.2016 01:13, schrieb Jon Brase:
> Gary,
>
> As to "why change", because I thought Hans was saying I had PPS wired to
> the wrong pin.
>
> I know I'm getting PPS in PPS test,  I know I'm not in gpsmon, and I'm
> not sure if I am in GPSD.
>
>
> -------- Original message --------
> From: "Gary E. Miller" <address@hidden>
> Date:03/03/2016 15:27 (GMT-06:00)
> To: Jon Brase <address@hidden>
> Cc: MAYER Hans <address@hidden>, address@hidden
> Subject: Re: [gpsd-users] Is GPSD receiving PPS?
>
> Yo Jon!
>
> On Thu, 03 Mar 2016 15:20:50 -0600
> Jon Brase <address@hidden> wrote:
>
>  > Ok, so my understanding at this point is that GPSD needs the PPS
>  > signal to go to the GPIO pin that the Pi uses for serial carrier
>  > detect,
>
> 'needs' is a bit strong.  gpsd can use PPS any way you can get it into
> the system.  If ntpd can read it, gpsd can read it.
>
> Details on the preferred method are in the gpsd INSTALL file.
>
>  > I can't just have the kernel use an arbitrary pin?
>
> Sor ot, but the kernel only knows how to do KPPS on some types of
> pins.  One again, same ffor gpsd and ntpd.
>
>  > I'd used a
>  > hardware setup walkthrough that recommended assigning GPIO pin 18 on
>  > the Pi on the basis of adjacency to the serial pins,  but I'm not
>  > sure it itself is a serial pin.
>
> gpsd does not care, since ppstest works you have it good enough.
>
>  > Anyways,  shouldn't be too much
>  > trouble to change, just moving a jumper and editing my boot
>  > parameters.
>
> Why change?
>
>
>
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
> address@hidden  Tel:+1 541 382 8588