[gpsd-users] GPSD issues on Raspberry Pi running Raspbian

[Pedro Vaz Teixeira]

Hi,

I am trying to setup a raspberry pi (model B rev 1.0) as a Stratum 1 microserver, and am following the procedure described in [1]. So far, I've had mixed results: while I've had to change some of the build commands [2], I have been able to build both gpsd and ntpsec on the raspi. The one issue blocking me right now is that I am unable to have gpsd output time notifications via shared memory (confirmed by ntpshmmon showing no output and ntpq -p showing a reach of zero for both gps and pps sources).

gpsd -h shows (usage info removed):

The following driver types are compiled into this gpsd instance:
NMEA0183
MTK-3301
u-blox
PPS
# n: mode switch, b: speed switch, c: rate switch, *: non-NMEA packet type.
# Socket export enabled.
# Shared memory export enabled.
# Time service features enabled.
# PPS enabled.

Running gpsd with debug output shows it is not able to open pps1 (which does not exist; the actual pps source is at /dev/pps0 and known to work via ppstest /dev/pps0) :
./gpsd -N -n -D 3 /dev/ttyAMA0
gpsd:INFO: launching (Version 3.17~dev)
gpsd:INFO: listening on port gpsd
gpsd:INFO: stashing device /dev/ttyAMA0 at slot 0
gpsd:INFO: SER: opening GPS data source type 2 at '/dev/ttyAMA0'
gpsd:INFO: SER: speed 9600, 8N1
gpsd:INFO: gpsd_activate(2): activated GPS (fd 4)
gpsd:INFO: KPPS:/dev/ttyAMA0 running as 1000/1000, cannot open /dev/pps1: Permission denied
gpsd:WARN: KPPS:/dev/ttyAMA0 kernel PPS unavailable, PPS accuracy will suffer
gpsd:INFO: PPS:/dev/ttyAMA0 ntpshm_link_activate: 1
gpsd:INFO: device /dev/ttyAMA0 activated
gpsd:INFO: running with effective group ID 1000
gpsd:INFO: running with effective user ID 1000
gpsd:INFO: startup at 2017-02-22T17:46:03.000Z (1487785563)
gpsd:INFO: /dev/ttyAMA0 identified as type NMEA0183, 0 sec @ 9600bps
gpsd:WARN: can't use GGA time until after ZDA or RMC has supplied a year.
gpsd:WARN: MTK NACK: 424, reason: Unsupported
gpsd:INFO: PRN= 14 az= 11 el=79 (0.036408, 0.187303, 0.981627)
gpsd:INFO: PRN= 31 az=283 el=71 (-0.317224, 0.073237, 0.945519)
gpsd:INFO: PRN= 32 az= 99 el=63 (0.448401, -0.071020, 0.891007)
gpsd:INFO: PRN= 25 az= 64 el=49 (0.589662, 0.287597, 0.754710)
gpsd:INFO: PRN= 26 az=192 el=26 (-0.186870, -0.879153, 0.438371)
gpsd:INFO: PRN= 10 az=173 el=22 (0.112995, -0.920273, 0.374607)
gpsd:INFO: PRN= 12 az= 38 el=14 (0.597374, 0.764603, 0.241922)
gpsd:INFO: PRN= 29 az=110 el= 8 (0.930548, -0.338692, 0.139173)

The pps module has been loaded:
lsmod | grep -i pps
pps_ldisc               2389  0
pps_gpio                2993  0
pps_core                8756  2 pps_ldisc,pps_gpio

Running gpsd using pps0 requires sudo, and yields:

sudo ./gpsd -N -n -D 3 /dev/pps0
gpsd:INFO: launching (Version 3.17~dev)
gpsd:INFO: listening on port gpsd
gpsd:INFO: stashing device /dev/pps0 at slot 0
gpsd:INFO: KPPS:/dev/pps0 RFC2783 path:/dev/pps0, fd is 4
gpsd:INFO: KPPS:/dev/pps0 pps_caps 0x1151
gpsd:INFO: KPPS:/dev/pps0 have PPS_CANWAIT
gpsd:WARN: KPPS:/dev/pps0 missing PPS_CAPTURECLEAR, pulse may be offset
gpsd:INFO: KPPS:/dev/pps0 kernel PPS will be used
gpsd:INFO: PPS:/dev/pps0 ntpshm_link_activate: 0
gpsd:INFO: device /dev/pps0 activated
gpsd:INFO: KPPS:/dev/pps0 kernel PPS timeout Interrupted system call
gpsd:INFO: KPPS:/dev/pps0 kernel PPS timeout Interrupted system call
gpsd:INFO: running with effective group ID 20
gpsd:INFO: running with effective user ID 65534
gpsd:INFO: startup at 2017-02-22T17:50:11.000Z (1487785811)

...and still no ntpshmmon output. Am I missing something?

Thanks in advance, and kind regards,

Pedro

[1] https://www.ntpsec.org/white-papers/stratum-1-microserver-howto/
[2] for instance, need to build gpsd with several additional scons options, otherwise I won't get the necessary gpsd clients (e.g. ntpshmmon and cgps)