Re: [gpsd-dev] Possible error report

[Andy Walls]

On Fri, 2013-11-08 at 10:21 -0500, Eric S. Raymond wrote:
> Andy Walls <address@hidden>:
> > My experience with the Trimble Condor is that the default PPS pulse
> > width is about 4 microseconds.  You can send probably send a $PMTK
> > sentence to program a wider pulse in the NVRAM settings.
> 
> We can, of course, send that sentence from the driver once we know
> how it should be composed.

You don't want to send it every time.  You'll end up needlessly
shortening the life of its NVRAM.


FWIW, an end user only need do the following once for a Trimble Condor.

With gpsd running, assuming the device has a 16.368000 MHz oscillator,
and a desired PPS pulse width of 1/128 seconds (127875/16368000
seconds):

1. In window 1 watch for $PMTK response from the device:

        # gpspipe -r | grep '$PMTK'


2. In window 2 type this to query the current setting:

        # export FOO=`gpsctl  -t MTK-3301 -e -x '$PMTK424'`
        # echo $FOO
        $PMTK424*30
        # echo $FOO > /dev/ttyS0   (or whatever serial device)


3. In window 1 observe the current setting:

        $PMTK424,0,0,1,0,69*12


4. In window 2 type this to change the setting:

        # export FOO=`gpsctl  -t MTK-3301 -e -x '$PMTK324,0,0,1,0,127875'`
        # echo $FOO
        $PMTK324,0,0,1,0,127875*14
        # echo $FOO > /dev/ttyS0   (or whatever serial device)


5. In window 1 observe the acknowledgment:

        $PMTK001,324,3*35


6. In window 2 type this to query the new, current setting:

        # export FOO=`gpsctl  -t MTK-3301 -e -x '$PMTK424'`
        # echo $FOO
        $PMTK424*30
        # echo $FOO > /dev/ttyS0   (or whatever serial device)


7. In window 1 observe the new, current setting:

        $PMTK424,0,0,1,0,127875*13



Regards,
Andy