Stuart Blake Tener <[email protected]> writes:
> GPSD users, developers, et alia:
>
> I have a General Dynamics GD8200 laptop that is inclusive of an
> internal GPS receiver. I was able to get GPSD running and cgps does
> show the satellites it sees, etc... However, I am a bit lost as to how
> to ascertain if I have pps capability and how to configure the
> software such that I can access it for setting the time on my laptop.
1) Read carefully:
https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html
2) Read the manual for your laptop and see if the 1 pps signal from the
GNSS receiver is hooked to GPIO or DCD :-)
> However, if indeed the GPS internal to my laptop does not have PPS
> capability, I am wondering if and how I can use the time within the
> GPS strings to set the clock in the laptop as well. I realize it is
> less accurate, but I am not doing anything transactional with the
> laptop so if it is 10 to 20 seconds behind every day I really not that
> concerned about it.
Yes, you can do that. You can calibrate out the NMEA delay, or choose
to ignore it. It's probably around 100 ms, which appalls some but not
all -- but your receiver may be odd. For 3 USB receivers, on a RPI3
running NetBSD, I have offsets from 0.044s to 0.116s. I've set that up
with ntpd; I have no idea how to enter an offset into gpsd. But... wait
for it... if I wanted to do that I'd read the linked document first, and
then the source code.
