Hi all,
I'm pretty new to gnuradio and have mostly been sticking to the flowgraphs. The functionality I was after was to have a display of what my USRP X310's were reading, as well as some controls to alter frequency and the like, and a button that would record what was being read while it was pressed. A trimmed down version is shown in the picture I attached, where the 'Enabled' field of the copy block is tied to a push button.
What I've found is that the copy block works well for feeding the IQ data through, and looks good both on the waterfall display in the graph, as well as when the resulting file is read from a metadata source. On the other hand, the headers associated with that metadata are effectively buffered by the copy block, resulting in a mismatch between the raw IQ data and the associated headers.
As an example, if while watching the display for 20 seconds, I want to save the first two seconds and the last two seconds (having seen something interesting in the display perhaps), I would press the record button accordingly, and the file would look right when played back, but the headers associated with those recordings would be the headers for the first 4 seconds of the 20 second run, not the first 2 and last 2 seconds.
I think this is a bug in the copy block, as I do not know when that performance would be desired.
If anyone knows of any ways to achieve this functionality I would greatly appreciate any and all assistance. I've tried to attain the same functionality with the selector block, but that behaved somewhat erratically and some cursory research agreed with that diagnosis. I'm running the most recent grc on ubuntu with 4 USRP x310's. As a worst case scenario I have considered manual documentation in lieu of headers, but I thought the idea of a record button would be pretty useful to a lot of people, so I'd love to have a more elegant solution.
Thanks in advance,
Mike G
