[gpsd-dev] Time Bug with multiple GPS receivers

[Brotherton, Brett]

I am trying to run with 2 GPS receivers (one u-blox and one sirf based).  The ublox has no fix but the sirf does and I should be able to get valid data from it.  However the timestamp jumps all over the place and is not right.  Below is an output from gpsmon –a –D 9. 

 

The first SiRF timestamp of 1519676009 (0x5A946A69) all subsequent timestamps are wrong and examing the hex values it appears the lower 2 bytes are good but the upper 2 bytes are wrong (eg next value of 2138991210 is 0x7F7E6A6A).  If I run gpsd with just one device everything works fine but running with the 2 consistently gives bad timestamps.

 

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;1519676009.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=1519676009.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=0

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=1554596167.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x04, seen=0x00, time:2138991210.00, leap:17

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;2138991210.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=2138991210.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=9

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=-2121055928.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;-1536660885.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=-1536660885.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=0

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=-1501740727.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;-917345684.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=-917345684.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=0

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=-882425526.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x04, seen=0x00, time:-298030483.00, leap:17

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;-298030483.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=-298030483.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=10

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=-263110325.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;321284718.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=321284718.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=0

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

gpsmon:DATA: NAVSOL: time=nan lat=0.00 lon=0.00 alt=-18.00 track=0.00 speed=0.00 climb=0.00 mode=1 status=1 used=0

gpsmon:PROG: UBX_NAV_TIMEGPS

gpsmon:DATA: TIMEGPS: time=356204876.00 leap=17, mask={TIME}

gpsmon:DATA: packet type 11 from tcp://localhost:2947 with {ONLINE|TIME|PACKET|PPSTIME}

gpsmon:PROG: SiRF: NTPD valid time MID 0x02, seen=0x00, time;940599919.00, leap:17

gpsmon:DATA: SiRF: MND 0x02: time=940599919.00 lat=39.90 lon=-105.13 alt=1666.90 track=0.00 speed=0.00 mode=3 status=1 hdop=0.80 used=0

gpsmon:DATA: packet type 4 from tcp://localhost:2947 with {ONLINE|TIME|LATLON|ALTITUDE|SPEED|TRACK|CLIMB|STATUS|MODE|DOP|PACKET|USED|CLEAR|REPORT|PPSTIME}

gpsmon:PROG: SiRF: THR 0x09: SegStatMax=0.000, SegStatLat=  0, AveTrkTime=0.000, Last MS=0

 

 

Thanks,

 

-Brett Brotherton