[Discuss-gnuradio] GPS Time

[Jawad Seddar]

Hi all, 

Yesterday, I decided to update from GNU Radio 3.7.7.1 + UHD 3.8.4 to GNU Radio 3.7.9 + UHD 3.9.1.

I used pybombs and everything went well, my OOT modules compile and my blocks run just like they used to.

My issue comes from the time that is set on the USRP. It seems like the time on the device is not set to use the GPSDO. After doing some digging, I noticed that this commit might be responsible : https://github.com/EttusResearch/uhd/commit/f4f3ce2550aba933b5f4d310d82a42a41ce3f6a1 .

So I tried setting the time source as GPSDO on my USRP source block (in GRC) but that doesn't seem to be working. I still get something  (in the tens of thousands) that is way below what it should be (I get the time on the USRP by looking at the rx_time tag available at the beginning of a received sample stream).

If I run a python CLI and setup a usrp_source then set the time manually to the gps_time, then the time is somewhat correct. 

Am I missing a step when setting up my usrp_source in GRC?

Thanks,

Jawad