ntpsec is ignoring PPS

[folkert]

> > PPS(0) is a regular garmin lvc18, while PPS(1) is a GPS disciplined
> > oscillator, this one: http://www.leobodnar.com/shop/index.php?main_page=produc
> > t_info&cPath=107&products_id=234 The GPSDO emits a 10MHz signal that is
> > divided to 1PPS using a "picdiv" (http://www.leapsecond.com/pic/picdiv.htm ).
> > As suggested by the website, a 100nF capacitor has been connected.
> 
> I think you are missing the key step.
> 
> The PPS from a GPS unit is carefully setup (by the GPS box) to start at the 
> start of a UTC second.
> 
> The picdev doesn't know anything about UTC.  Its pulses will be 1 second apart 
> (if your 10 MHz is accurate), but they will start at an arbitary time relative 
> to the start of a UTC second.

Indeed! Yesterday evening I was just installing a picdiv that I can sync
to the start of a second (via a secondary gps).
This morning I looked at the results and now ntp chooses the gpsdo and
no longer the garmin! That's great news!

> Does the picdev have a way to move the PPS around so you can adjust the 
> PPS-UTC offset? That would need a good PPS to compare it to  If nothing else, 
> you can short out the clock input.

The 'PD11' can.

What I now did is, connect the 'arm' pin of the pic to a gpio pin of the
pi and the sync to the pps of a secondary gps (a garmin). So now
whenever the pi resets, I can (even remote) just pull that arm pin low
for a second and then up again (it actually starts low).

     remote           refid      st t when poll reach   delay   offset   jitter
xPPS(0)          .PPS.            0 l   14   16  377   0.0000  -0.0183   0.0023  <-- garmin
oPPS(1)          .PPS.            0 l   13   16  377   0.0000   0.0019   0.0033  <-- gpsdo
 nl.pool.ntp.org .POOL.          16 p    -  256    0   0.0000   0.0000   0.0019
+y.ns.gin.ntt.ne 204.2.140.74     2 u   15   64  377   9.4229   0.7682   2.5404
+mail.emuadmin.c 51.75.141.62     3 u   45   64  377  11.6021   2.2178   2.3358
+bandersnatch.ro 193.79.237.14    2 u   22   64  377  11.7751   2.0661   2.9364
+arethusa.tweake 193.79.237.14    2 u   26   64  377   9.4176   1.1346   5.6991
+ntp1.lonet.org  131.176.107.13   2 u   32   64  377  10.3465   1.7332   9.8990
+time.cloudflare 10.20.14.167     3 u   35   64  377  10.0105   1.7275   4.8161
*ntp4.bit.nl     .PPS.            1 u    8   64  377   9.4332   1.2232   4.8248

looking great!