I was not setting the spp size for the radio or DDC which was leading the FFT failure. Setting the spp block arguments here fixed the issue with the FFT.
Being unable to halt the graph came from an unrelated issue on the PC side of the graph. Thanks, Rylee From: USRP-users <[email protected]> Date: Thursday, January 21, 2021 at 1:43 PM To: Rob Kossler <[email protected]> Cc: [email protected] <[email protected]> Subject: Re: [USRP-users] RFNoC 4 FFT with GNURadio Rob, I did set this explicitly when I tried using the UHD Python library so I must have a different issue there. But I did forget to set it in GNURadio which did change the behavior. Now when streaming, the first FFT length number of samples are valid data but all data samples after that are zero and the graph cannot be halted. Thanks, Rylee From: Rob Kossler <[email protected]> Date: Thursday, January 21, 2021 at 1:09 PM To: Mattingly, Rylee <[email protected]> Cc: [email protected] <[email protected]> Subject: Re: [USRP-users] RFNoC 4 FFT with GNURadio Perhaps try setting the radio SPP = FFT length? On Thu, Jan 21, 2021 at 10:38 AM Mattingly, Rylee via USRP-users <[email protected]<mailto:[email protected]>> wrote: Hi all, I am trying (and failing) to get an RFNoC image with the provided FFT working with GNURadio. I am using an X310 connected with a 1Gig ethernet and building images in the HG configuration. I used the knowledge base article: "Getting Started with RFNoC in UHD 4.0" (linked here: https://kb.ettus.com/Getting_Started_with_RFNoC_in_UHD_4.0<https://urldefense.proofpoint.com/v2/url?u=https-3A__kb.ettus.com_Getting-5FStarted-5Fwith-5FRFNoC-5Fin-5FUHD-5F4.0&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=WRMR1ToHPgCgrxeKlDxekAf8zkWOnmzADEnOeDFFLx4&e=>) to add the FFT to the default image. The resulting image core with FFT can be found here: https://pastebin.com/xLqyx7qS<https://urldefense.proofpoint.com/v2/url?u=https-3A__pastebin.com_xLqyx7qS&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=0apXU3AXxgv1drH2fIZHdjJ3lbHLbX9K2fImIOo5Uns&e=> The uhd probe shows the fft correctly connected to through its own SEP. However, when I attempt to run a flowgraph containing the FFT I get a recv() timeout error and then blocks will not flush unitl the USRP is reset. One of the many flow graphs I have tried, and the consistent error are shown in the screenshots here: https://pasteboard.co/JKFUlrH.png<https://urldefense.proofpoint.com/v2/url?u=https-3A__pasteboard.co_JKFUlrH.png&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=JlqF2Qp2KClHzn0mvHswomA11v3zTzsa6gIGVLxN3FY&e=> and here: https://pasteboard.co/JKFTHji.png<https://urldefense.proofpoint.com/v2/url?u=https-3A__pasteboard.co_JKFTHji.png&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=XtmxPj8fXQeJhRCuLKoCuFccvXZOvYLKTJl6oSunz00&e=> I then tried using the UHD Python API deriving from the example shown in the GRCon20 session "Exploring RFNoC with the UHD Python API" by Aaron Rossetto. Here I find that a static loopback example like Aaron presented with the FFT worked with one length of samples but trying to extend that for streaming from the radio creates the same behavior that is exhibited with GNURadio. The only way that I can get the FFT to execute correctly is if I stream exactly one FFT length of samples. Any larger number of samples from the radio (even length multiple) will crash the block and requires a power cycle to be able to flush again. Loopback example code: https://pastebin.com/03dScZvB<https://urldefense.proofpoint.com/v2/url?u=https-3A__pastebin.com_03dScZvB&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=sLbsQ4340BLt3mlqTSjBY7_4WeI-k3OCtGa0NXtXPT0&e=> Streaming test code: https://pastebin.com/WQRn7UhH<https://urldefense.proofpoint.com/v2/url?u=https-3A__pastebin.com_WQRn7UhH&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=X6qNPBtpTwb5Nic40FgQofh-q3hb5bKlU7LKdYTv_zI&e=> I have been able to build and use custom RFNoC blocks sucessfully with GNURadio on this installation of UHD 4.0, GNURadio 3.8 and gr-ettus. Thank you, Rylee _______________________________________________ USRP-users mailing list [email protected]<mailto:[email protected]> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.ettus.com_mailman_listinfo_usrp-2Dusers-5Flists.ettus.com&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=IRw4yqTQyxVHnwRt0l8Smy70YsBQKXCywQEkDFJVQQc&m=1s6oj0M92rhUqhJ9cwnA1ZVYmoTHIKZPk3Ssa4lGRSA&s=aM0JcEUdk219VkyfzdD1qBVqRMWztDC98fCMR6xZu0Y&e=>
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