[time-nuts] SiRF GPS receivers: GlobalSat MR-350P

Chris Kuethe chris.kuethe at gmail.com
Wed Jan 23 13:12:01 EST 2008

On Jan 23, 2008 1:44 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
> The context for this query is that I'm looking for inexpensive GPS units with
> a PPS output to connect up to ntpd.
> Is anybody familiar with these units?

I've used other globalsat receivers based on both the SiRFstarII and
SiRFstarIII architectures...

> I just wired one up.  The PPS signal is only 1 microsecond wide.

Yep. That's consistent with the description I've seen of the sirf3 1PPS signal.

> The PPS from my Z3801A is 10 microseconds wide.  I can deal with that.  The
> extra factor of 10 is inconvenient.  (at least so far)
> The Garmin GPS 18 LVC  has a command to adjust the PPS pulse width, but
> that's at the granularity of 20 ms rather than the microsecond range.  I just
> scanned the SiRF binary protocol manual and NMEA manual and didn't see
> anything.  (But I might have missed it.)

There is no command to do that. Sorry.


GDB has a 'break' feature; why doesn't it have 'fix' too?

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