Re: [Discuss-gnuradio] Timestamps USRP N210
Hi Josh, > If you want the timestamps, you can use UHD directly (see the > examples/rx_timed_samples.cpp). thanks for the quick response. I did not have much time to check out the timed example, but will do that as soon as possible. > If you are looking to align multiple channels, the uhd source block will > do that automatically when you set it up for multiple channels. I am actually having two USRPs connected via a switch to a single computer. In the flowgraph I have two times the same branch, starting from each of the UHD source blocks. The USRPs should listen to the same stuff and I want to be able to compare their observations (samples), thus they need to should start sampling at the same time (or I have to know their exact offset). > Or from gnuradio, you can make a trivial mod to the source block's work > function to intercept the RX metadata and create a tag for each > timestamp. This tag will get propagated down the chain of processing blocks. This sounds pretty good. I will have a look what I can do with that. Sebastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Timestamps USRP N210
On 08/03/2011 05:08 PM, Sebastian Bader wrote: > Hello everyone, > > I am currently working with multiple receivers of USRP N210s. I would > like to correlate the received signal of multiple receivers and > therefore require them to start sampling at the same time. Is there a > good way to implement that? > > Regarding to that issue I was curious to see sample timestamps. I have > seen in various other threads that people have addressed this issue, > but I could not find any detailed information on how to get exact > (usec - nsec accuracy) timestamps. Can anyone tell me how to extract > timestamps from the received samples? Or if I have overseen it, tell > me where I can find that information? > If you are looking to align multiple channels, the uhd source block will do that automatically when you set it up for multiple channels. If you want the timestamps, you can use UHD directly (see the examples/rx_timed_samples.cpp). Or from gnuradio, you can make a trivial mod to the source block's work function to intercept the RX metadata and create a tag for each timestamp. This tag will get propagated down the chain of processing blocks. -josh ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Timestamps USRP N210
Hello everyone, I am currently working with multiple receivers of USRP N210s. I would like to correlate the received signal of multiple receivers and therefore require them to start sampling at the same time. Is there a good way to implement that? Regarding to that issue I was curious to see sample timestamps. I have seen in various other threads that people have addressed this issue, but I could not find any detailed information on how to get exact (usec - nsec accuracy) timestamps. Can anyone tell me how to extract timestamps from the received samples? Or if I have overseen it, tell me where I can find that information? Thanks, Sebastian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
