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Re: [Discuss-gnuradio] UHD: samples alignment
From: |
Josh Blum |
Subject: |
Re: [Discuss-gnuradio] UHD: samples alignment |
Date: |
Sat, 3 Jul 2010 09:27:53 -0700 |
> 1- Is it enough to do this? Shouldn't I tell the USRP2 to start streaming at
> a specific timestamp? I have looked into the UHD files but wasn't able to
> spot a function to do this, though.
>
yes, the stream_cmd must have a time stamp specified so both usrp2s
start streaming at the exact same time. Currently, it defaults to
stream now:
http://www.ettus.com/uhd_docs/doxygen/html/structuhd_1_1stream__cmd__t.html
this change will require modifications to the gr-uhd source in the
call to issue_stream_cmd
> 2- If I don't use the clock_config, what are the defaults?
>
internal ref clock, sma pps
> 3- In the runtime, how can I print the received packet timestamp to make
> sure they are aligned?
>
print the first metadata.time_spec in the gr-uhd source work function
should you be willing to wait, I am working on exactly this issue of
multiple usrp2 alignment and I hope to push something up next week
when I get it all working.
-Josh