Re: Using gpsd

William G. Unruh __| Canadian Institute for|____ Tel: +1(604)822-3273
Physics&Astronomy _|___ Advanced Research _|____ Fax: +1(604)822-5324
UBC, Vancouver,BC _|_ Program in Cosmology |____ [email protected]
Canada V6T 1Z1 ____|____ and Gravity ______|_    theory.physics.ubc.ca/

On Tue, 19 Mar 2024, David Campbell wrote:

> [CAUTION: Non-UBC Email]
> 
> I missed the "For example" bit, thanks for the clarification.
> 
> Reading the documentation again, I only can get the first example to work, so there
> is no delay or offset.
> 
> # First option
> refclock SOCK /var/run/chrony.ttyS0.sock refid GPS

On my system, /var/run is a link to /run. I think it was at least 5 years ago
that it was switeched from /var/run to /run

> 
> # Second option
> refclock PPS /dev/pps0 lock NMEA refid GPS
> refclock SOCK /var/run/chrony.clk.ttyS0.sock offset 0.5 delay 0.1 refid NMEA nosele
> ct

That says that the system is .5 sec out? Hard to believe. Maybe you are using
the wrong part of the pulse (clear rather than assert?)

What makes you think you need the offset and delay set?

> On 3/19/24 17:39, Bill Unruh wrote:
>
>       On Tue, 19 Mar 2024, David Campbell wrote:
>
>             [CAUTION: Non-UBC Email]
>
>       ...
>             Also, the device path given by chrony is out of date and
>             the one given by gpsd works: that is
>             "/run/chrony.XXXX.sock" instead of
>             "/var/run/chrony.clk.XXXX.sock". If I am wrong about the
>             paths, I don't know how chrony works, but only the former
>             works for me.
> 
>
>       man chrony.conf
>
>             SOCK
>                      Unix domain socket driver. It is similar to the SHM
>       driver, but
>                      samples are received from a Unix domain socket instead
>       of shared
>                      memory and the messages have a different format. The
>       parameter is the
>                      path to the socket, which chronyd creates on start. An
>       advantage over
>                      the SHM driver is that SOCK does not require polling and
>       it can
>                      receive PPS samples with incomplete time. The format of
>       the messages
>                      is described in the refclock_sock.c file in the chrony
>       source code.
>
>                      An application which supports the SOCK protocol is the
>       gpsd daemon.
>                      The path where gpsd expects the socket to be created is
>       described in
>                      the gpsd(8) man page. For example:
>
>                          refclock SOCK /var/run/chrony.ttyS0.sock
>
>       See the words "For example:? Ie, the man page says to use what gpsd
>       says the the
>       path is.
>
>       Note that path could well be different for different versions of Linux.
> 
> 
> 
> 
>