[Discuss-gnuradio] How to check at which GPS time correspond the pps edge of set_time_next_pps()

[Bastien Auneau]

Hi

USRP N210, UHD 3.2.1, GPSDO Jackson Labs installed

windows7

Using set_time_next_pps()

How can I be sure at which GPS time (in seconds from 01/01/1970) the pps egde correspond to

So far, here is how I do :

_ get GPS time (get_mboard_sensors("gps_time")), let it be gps_t_0

_ set_time_next_pps(0, 1, 54000000)

_ add + 2 sec to gps_t_0. +1 because time is set at next PPS, +1 because this seems to be time needed to execute the sensor query on GPS (practically, I was always 1 sec behind, before this last +1)

This has shown to be stable in development lab, for the last few days.

But is there another mechanism to map the "next pps" to a GPS time (in seconds from 01/01/1970) ?

What bothers me, it's that the second +1 I add is based on the get_mboard_sensors("gps_time") execution time (approx 1 sec). But this may change randomly (depending on load, HW etc..)

Regards

Bastien