[USRP-users] get position and status info from N210's internal GPSDO

Michael West michael.west at ettus.com
Thu Oct 15 13:39:12 EDT 2015


Hi Anselm,

The time on the N210 is no longer set tot the GPS time automatically (as of
UHD 3.9.0), but it is fairly easy to do.  In Python:

# set clock and time sources to GPSDO
self.usrp.set_clock_source("gpsdo")
self.usrp.set_time_source("gpsdo")
# wait for PPS edge
t = self.usrp.get_time_last_pps()
while (t == self.usrp.get_time_last_pps())
    pass
# set the time from the GPS time
self.usrp.set_time_next_pps(self.usrp.get_mboard_sensor("gps_time").to_int()+1)
# wait for a second to make sure the time is set
time.sleep(1)

With that done, the time tags will be the GPS time.  Here are the calls to
get the other GPS sensor data:

self.usrp.get_mboard_sensor("gps_gpgga")
self.usrp.get_mboard_sensor("gps_gprmc")
self.usrp.get_mboard_sensor("gps_servo")
self.usrp.get_mboard_sensor("gps_locked")

You will more than likely have to write your own Python script to have
everything you need, but I hope this helps.

Regards,
Michael

On Mon, Sep 28, 2015 at 3:02 AM, Anselm Karl via USRP-users <
usrp-users at lists.ettus.com> wrote:

> Hi everone,
>
> I´ve got a N210 with an internal GPSDO. Besides the base band signal from
> the usrp i want to record the position (and maybe the gps receiver's
> status) to a (or several) files. And i want to reference the recorded base
> band signal to the gps time.
>
> The UHD manual says the VITA timestamps are set to gps time (if the gps
> receiver has reception). Does that mean the rx_time tag in gnu radio is gps
> time, too?
>
> Is it possible to do the position recording in GRC or will i have to do my
> own phyton script? Any example code would be great!
>
> --
> Mit freundlichen Grüßen
>
> *Anselm Karl*
>
>
> _______________________________________________
> USRP-users mailing list
> USRP-users at lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/attachments/20151015/2b61c6e9/attachment-0002.html>


More information about the USRP-users mailing list