Re: [gpsd-dev] PPS support

[Gary E. Miller]

Yo Eric!

On Sun, 5 Apr 2015 04:58:17 -0400
"Eric S. Raymond" <address@hidden> wrote:

> > Over the last couple of months, PPS display support has become a
> > non-brainer.  Thanks to the developers (I am looking at you, Mr
> > Miller), I have been meeting local enthusiasts, plugging their
> > devices into my laptop, and in every case, seeing both a PPS
> > display in PPS, and NTP locking onto it.  Note that all these
> > devices are "unbranded", bought off eBay.
> 
> Huh? What? We've had the devil's own time finding inexpensive
> PPS-capable devices.  Tell us more; where can we dig these up?

I've been using the MR-350P (Not the SiRF IV model) and the Garmin-18
LVC, both $50-ish.  You just need to look.

> > killall gpsd
> > gpsd -n /dev/ttyUSB0
> > /etc/init.d/ntp restart
> > gpsmon
> > (go for a smoke)
> > ntpq -pn
> 
> Gary, that looks to me like an improvement on this:
> 
> $ su - (or sudo -s )
> # killall -9 gpsd ntpd
> # ntpd -gN
> # sleep 2
> # gpsd -n /dev/ttyXX
> # sleep 2
> # cgps

Except,
        1. many users forget to 'su -' first
        2. gpsd often will not die without the -9
        3. /etc/init.d/ntp is Distro specific
        4. /etc/init.d/ntp is broken on Debian
        5. if you script or cut/paste without the sleep's it will fail.
        6. many users have no sky view, thus the cgps is essential

The main howto goes for least common denomiator and idiot proof.

Eric, I know you skip step 1, thus breaking RFC2783 PPS.
 
> But the technical content in the Time Service HOWTO is your baby and
> I don't want to change that without clearing with you.

That might be good in a distro specific part.  We'll need more of those.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
        address@hidden  Tel:+1(541)382-8588