Re: [gpsd-dev] New 0.5 draft of the SemPiTernal HOWTO

[Gary E. Miller]

Yo Frank!

On Thu, 5 May 2016 19:54:33 -0400
Frank Nicholas <address@hidden> wrote:

> Regarding the GPIO & edge detection issue in section:
> == Edge-detection issues and new HATs ==
> 
> Do we know if that issue still persists in the current kernel?  I
> thought I saw some post explaining how to check for it, but can’t
> seem to find it now...

Yes, the patch has not been accepted by LKML, no distros add it.

Simple to see:

address@hidden:~# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1462492791.999966543, sequence: 147766 - clear  0.000000000, 
sequence: 0
source 0 - assert 1462492792.999970614, sequence: 147767 - clear  0.000000000, 
sequence: 0
^C

No clear edge is every detected, but the assert ticks away.

Also note my pi2 has ntpd peers, so I know the assert it right on the money:

address@hidden:~# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
-SHM(0)          .GPS.            0 l    2   64  377    0.000  -115.17  87.356
*SHM(1)          .SHM.            0 l    1   64  377    0.000    0.028   0.008
+catbert.rellim. .SHM.            1 s   20   64  377    0.369    0.407   0.070
+spidey.rellim.c .GPS1.           1 s   38   64  376    0.355    0.025   0.021
-kong.rellim.com .SHM1.           1 s   64   64  377    0.313   -9.145   1.668
-backup.rellim.c 204.17.205.8     2 s   61   64  377    0.423    0.071   3.575

8 microSec jitter on PPS, 0.025 milliSec offset from my main GPS PPS server
(spidey).

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

pgplOHTmq_o6N.pgp
Description: OpenPGP digital signature