[DSP-10] A Clock Question

[Bob Larkin]

Mike,

The sentences that you show look standard. My original concerns had to do 
with your web page that does not show the last three characters, i.e., the 
asterisk and the hex check sum.

I bet the NMEA from the Jupiter will work just fine for clock setting, when 
we get the new code finished up and distributed.  The GGA is being sent 
from the Jupiter once a second, and probably started with a fixed 
relationship to the second being indicated in the time field.  Partial 
seconds of variation from second-to-second are OK, but not more than a 
second of variation.  The latency can be any amount of time, as long as it 
doesn't hop around too much.  The existing DSP-10 parsing will probably 
work OK, as they do with the Sandpiper and Garmin that have been tested.

Thanks, 73,
Bob  W7PUA

At 03:07 PM 3/14/2006, Mike Seguin wrote:
>Here's an actual raw output (48k6 baud) from the Jupiter engine when locked:
>
>$PRWIZCH,09,7,19,2,00,0,21,7,14,7,18,7,15,7,28,0,22,7,26,7,29,2,03,2*44
>$GPGGA,225859,4430.5573,N,07315.1368,W,1,07,1.25,66.8,M,-32.4,M,,*7B
>$GPGSA,A,3,09,21,14,18,15,22,26,,,,,,1.92,1.25,1.46*0B
>$GPRMC,225859,A,4430.5573,N,07315.1368,W,0.000,0.0,140306,15.9,W*41
>$PRWIZCH,09,7,19,2,00,0,21,7,14,7,18,7,15,7,28,0,22,7,26,7,29,2,03,2*44
>$GPGGA,225900,4430.5573,N,07315.1368,W,1,07,1.25,66.7,M,-32.4,M,,*79
>$GPGSA,A,3,09,21,14,18,15,22,26,,,,,,1.92,1.25,1.46*0B
>$GPGSV,3,1,11,18,79,350,48,15,64,244,45,09,59,124,47,21,51,193,47*7D
>$GPGSV,3,2,11,22,42,300,42,26,25,057,35,14,18,247,35,29,17,060,25*7B
>$GPGSV,3,3,11,03,08,290,32,19,06,325,22,28,02,026,00*4E
>$GPRMC,225900,A,4430.5573,N,07315.1368,W,0.000,0.0,140306,15.9,W*4C
>$PRWIZCH,09,7,19,2,00,0,21,7,14,7,18,7,15,7,28,0,22,7,26,7,29,2,03,2*44
>$GPGGA,225901,4430.5573,N,07315.1368,W,1,07,1.25,66.6,M,-32.4,M,,*79
>$GPGSA,A,3,09,21,14,18,15,22,26,,,,,,1.92,1.25,1.46*0B
>$GPRMC,225901,A,4430.5573,N,07315.1368,W,0.000,0.0,140306,15.9,W*4D
>
>73,
>Mike, N1JEZ
>"A closed mouth gathers no feet"
>
>----- Original Message -----
>From: "kd7ts" <kd7ts at ispwest.com>
>To: "Discussion of DSP-10 2-meter transceiver" <dsp-10 at mailman.qth.net>
>Sent: Tuesday, March 14, 2006 1:14 PM
>Subject: Re: [DSP-10] A Clock Question
>
>
> > this is a sample from 5.6.1.3, table 5-47 GGA messages
> >
> > $GPGGA,222435,3339.7334,N,11751.7598,W,2,06,1.33,27.0,M,-34.4,M,7,0000*41
> >
> > from the "Designers Guide of the Zodiac Family" for the Conexant GPS
>engines.
> >
> > It appears identical in form and fields with the NMEA-0183 spec.
> >
> > 73 Mike KD7TS
> >
> >
> > Bob Larkin wrote:
> > > Hi Mike,
> > >
> > > Is the relationship between the NMEA GGA sentence and the actual GPS
> > > time fixed?  If so, it can be handled by the current implementation.
> > > This allows for an offset between the end of GGA sentence and the 1PPS
> > > pulse timing.  The current software keys on GGA for minutes and seconds,
> > > but also reads GSV when they are available and summarizes that data.
> > > GSV can come anytime, and the latest are used.
> > >
> > > Rockwell binary would fit into the current scheme, but if NMEA works,
> > > that is easier, as it i there. The UT+ runs in binary.
> > >
> > >  Also, page 8 of your freq reference paper:
> > >
>http://mysite.verizon.net/n1jez/osc/A%20Simple%20GPS%20Stabilized%2010%20MHz%20Oscillator.pdf
> > >
> > > shows the NMEA strings without an ending asterisk and check sum. I
> > > assume these are there in real life?
> >
> > _______________________________________________
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> > DSP-10 at mailman.qth.net
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>
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