Thanks to Josh and Marcus for their comments. The set_time_now command works! After I put it in, the earlier observed 0.5 sec offset between the 2 USRP became ~0.1 second. So there is still work to do. I guess my options are:
1. Make the set_start_time command to work. My question is how I can make it work in python. I hand edited the set_time_now command to embed in the initialization part of the top_block.py code generated from GRC (which has worked). Do I just hand edit the set_start_time just following that command? Now the problem is that after set_time_now, the USRP time is sync'd to the system time. But what is the argument I should give to set_start_time? 2. The other option is to get the metadata out for the samples collected. >From what I read, it looks like one cannot do it in GRC, but have to edit the cpp source code. Is there an example somewhere of how this is done? Thanks very much, LD -----Original Message----- From: LD Zhang [mailto:[email protected]] Sent: Friday, January 04, 2013 5:38 PM To: 'Marcus D. Leech'; '[email protected]' Subject: RE: [Discuss-gnuradio] How do I capture of the time of USRP N210 samples with host computer system time? Great! Thanks. I tried to import time and it works. Now I just have to see if this is sufficient for my sample gather timing or I still have to get the timestamp of the first sample using metadata and such. LD -----Original Message----- From: Marcus D. Leech [mailto:[email protected]] Sent: Friday, January 04, 2013 4:15 PM To: LD Zhang; [email protected] Subject: Re: [Discuss-gnuradio] How do I capture of the time of USRP N210 samples with host computer system time? On 01/04/2013 07:03 PM, LD Zhang wrote: > Hello, > > I tried the following command in python: > >> python: >> usrp_source.set_time_now(uhd.time_spec_t(time.time()) >> > It doesn't seem to work. Looks like the "time.time()" is wrong? Looked > up an earlier example: > > set_time_now(uhd::time_spec_t(0.0), 0) > > The syntax looks different. But this may be doing something different > from my intention which is to sync the USRP time to the host system > time. I am still searching for the right syntax for this command. Any > help is appreciated. > > LD > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > You'll have to put an: import time In your python -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
