> I don't see a streaming time specified in the generated code that you
> supplied.
I used
self.blocks_head_0 = blocks.head(gr.sizeof_gr_complex*1,
(int(6*samp_rate)))
and
self.connect((self.blocks_head_0, 0), (self.blocks_file_sink_0, 0))
self.connect((self.blocks_interleave_0, 0), (self.blocks_head_0, 0))
and since I interleave 2 complex streams I expect 6*samp_rate to last 3 seconds
> Try setting a "Start Time" in your UHD source block of perhaps "2.0" --
> this will arrange for streaming to commence 2 seconds
> after it resets the timestamp clock. Otherwise, streaming is started
> at some random time.
OK will try that. The setting in the Python script is the one provided by GRC.
Indeed adding at the end of the __init__(self) generated by GRC
curr_hw_time = self.uhd_usrp_source_1.get_time_last_pps()
self.uhd_usrp_source_1.set_time_next_pps((curr_hw_time+1.0))
self.uhd_usrp_source_1.set_start_time((curr_hw_time+1.1))
seems to do the trick with the 1st PPS edge always aligned to the same sample
index.
Too bad GRC does not generate the appropriate code: I cannot see any impact when
changing the Start Time (seconds) of the UHD: USRP Source block.
> Also, rather than looking for the PPS edge in the data, the "File Meta
> Sink" includes meta-data, like timestamps-as-seen-by-the-radio.
The PPS edge was just to check the consistency of the date last access date
(which seems consistent with my expectation) and the position of the actual
data (which I cannot figure out by analyzing the IQ stream). I did check that
the
meta data are consistent (with my above example the data start streaming at 1.1
s
of the internal timer of the SDR source) but my objective is the comparison with
the system time, which I am now on better tracks to achieve with these inputs.
Thanks.
_______________________________________________
USRP-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]
_______________________________________________
USRP-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]
