[LinuxPPS] ntpd configuration with local clock and pps

[Udo van den Heuvel]

Harun Alasar wrote:
> On Fri, May 15, 2009 at 6:43 PM, Udo van den Heuvel <udovdh at xs4all.nl 
> <mailto:udovdh at xs4all.nl>> wrote:
> 
>     Harun Alasar wrote:
> 
>         I also added some printfs to ntpd source(only refclock_atom.c)
>         for debugging and verified that ntpd can open the device and
>         fetch data from it. But ntpq> associations command says that pps
>         source is rejected by ntpd. What could be the reason for that ?
>         Thank you.
> 
> 
>     How does ntpd know what timestamp belongs to the pps?
>     Add NMEA, at least.
 >
 > But I don't have a NMEA source.. I want to use only local system clock
 > and a pps source to synchronize time. Is it possible ?

Well, ntp knows (using pps) when a second starts.
But it does not know what timestamp to add to that second.
NMEA is a way.
Internet connection to other ntp boxes is a way.
Etc.