[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[gpsd-users] PPS Problem with U-blox NEO-7 GPS Under Debian 7.5 (Wheezy)
From: |
Benedikt Kleinmeier |
Subject: |
[gpsd-users] PPS Problem with U-blox NEO-7 GPS Under Debian 7.5 (Wheezy) |
Date: |
Wed, 21 May 2014 15:53:55 +0200 |
Hi,
I try to synchronize time of different computers in a Car2X scenario.
I configured gpsd and nptd successfully using the official HOWTO
(http://www.catb.org/gpsd/gpsd-time-service-howto.html):
address@hidden:~# ntpq -p
remote refid st t when poll reach delay offset
jitter
==============================================================================
.
*SHM(0) .GPS. 0 l 39 64 377 0.000 -24.724
19.001
SHM(1) .PPS. 0 l - 64 0 0.000 0.000
0.000
I also configured ntpd to use the PPS signal, but gpsd doesn't process the PPS
signal provided by the u-blox NEO-7 GPS (see above: "reach" is 0).
I'm not sure if it is a hardware or software problem. I use a slightly modified
Intel Atom board. From the manual: "[.] to get exact time informations a CPLD
from Lattice is connect to the timepuls pin of the NEO-7. The CPLD is connected
to the computer board using the LPC bus."
Linux recognizes a PPS device (dmesg | tail):
.
[ 36.215407] pps_core: LinuxPPS API ver. 1 registered
[ 36.215415] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo
Giometti <address@hidden>
[ 36.217828] pps_ldisc: PPS line discipline registered
[ 36.218396] pps pps0: new PPS source acm0
[ 36.218417] pps pps0: source "/dev/ttyACM0" added
But using the PPS signal fails:
address@hidden:~# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
time_pps_fetch() error -1 (Connection timed out)
.
Running gpsd in foreground reports an error (gpsd -n -N -D 4 /dev/ttyACM0):
.
gpsd:INFO: KPPS checking /sys/devices/virtual/pps/pps0/path, /dev/ttyACM0
gpsd:INFO: KPPS caps 1133
gpsd:WARN: KPPS kernel PPS will be used
gpsd:ERROR: PPS ioctl(TIOCMIWAIT) failed: 22 Invalid argument
gpsd:PROG: PPS gpsd_ppsmonitor exited???
Maybe someone has a clue how to narrow down the problem
Thank you,
Benedikt