If work() can reach this line: https://github.com/gnuradio/gnuradio/blob/maint-3.8/gr-digital/lib/corr_est_cc_impl.cc#L311
with an all-zero signal, there could be a /0 error. On Thu, Jul 2, 2020 at 4:04 PM Cameron Matson <ncmatso...@gmail.com> wrote: > Hi all, > > An update: I've noticed that when the flowgraph hangs it's usually because > the correlation estimator block is outputting a relatively larger 'amp_est' > tag (in my case this is normally a value < 1 but sometimes up to around > 10. When it freezes it is usually > 50). If I then close the GUI tab the > flowgraph doesn't actually finish until I hit the 'Kill' button in GRC. > Only after that the terminal will print ">>>Done (return code -15)" I > can't find anything on what that code might mean. Does anyone have any > idea? > > Thanks, > Cameron > > On Wed, Jul 1, 2020 at 5:31 PM Cameron Matson <ncmatso...@gmail.com> > wrote: > >> Hi all, >> I'm trying to send packet data from between two USRPs wirelessly using >> the slightly modified uhd_packet_tx/rx examples (attached). It appears >> that whenever the packet_rx block "finds" a correlation the entire flow >> graph hangs. I say "find" because in order to get any output from the >> correlation estimator block within packet_rx I have to set the threshold >> very low, so I'm not very confident that it's finding what it needs. I've >> tried playing around with the different encodings and header formats that >> are part of the example, but it doesn't seem to change anything. >> >> First question: what could be causing the rx flowgraph to hang? I know >> some of the downstream blocks in the packet_rx hier block use the tags the >> correlation estimator outputs. >> >> Second question: what are some things I can try to improve the detection >> in the first place? >> >> Thanks, >> Cameron >> >
