Using Ublox GPS module timing for control

Discussion in 'Automation & Control' started by camerart, Jun 6, 2019.

  1. camerart

    Thread Starter Senior Member

    Feb 25, 2013
    1,304
    40
    Hi,
    I'm using Ublox GPS modules and the NMEA DATA for positioning.

    There are different settings for the speed that the NMEA sentences are OUTPUT, the default is 1/SEC.

    READing all of the NMEA sentences takes time, and I wondered if the TIMEPULSE from the GPS could be used to time start of the READ.

    Here are the sentences for the GPS, showing the section I need (In RED)
    :
    ¦¦TIME$GPRMC,162254.00,A,3723.02837,N,12159.39853,W, TIME¦¦ 0.820,188.36,110706,,,A*74
    $GPVTG,188.36,T,,M,0.820,N,1.519,K,A*3F
    $GPGGA,162254.00,3723.02837,N,12159.39853,W,1,03,2.36,525.6,M,-25.6,M,,*65
    $GPGSA,A,2,25,01,22,,,,,,,,,,2.56,2.36,1.00*02
    $GPGSV,4,1,14,25,15,175,30,14,80,041,,19,38,259,14,01,52,223,18*76
    $GPGSV,4,2,14,18,16,079,,11,19,312,,14,80,041,,21,04,135,25*7D
    $GPGSV,4,3,14,15,27,134,18,03,25,222,,22,51,057,16,09,07,036,*79
    $GPGSV,4,4,14,07,01,181,,15,25,135,*76
    $GPGLL,3723.02837,N,12159.39853,W,162254.00,A,A*7C
    $GPZDA,162254.00,11,07,2006,00,00*63
    Then a gap before the next set.

    Assuming the sentences are always SENT in the same order, then if the READ was started sometime after the TIMEPULSE, so as to READ just before the [ $ ] of the GPRMC marked [ ¦¦ ] then stop READ just after.

    I'm guessing that two systems, in my case a BASE and REMOTE could be any distance apart, as the GPS clocks are universal, so this method may be used to coordinate two acts anywhere at the same time.

    Any thoughts please
    Camerart.
     
  2. camerart

    Thread Starter Senior Member

    Feb 25, 2013
    1,304
    40
    Hi,
    I've found a bit more about the TIMEPULSE.
    If I'm correct,that it is predictable, then it will suit my purposes.
    C
     
Loading...