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FFT data stream - not working
Solved!
MinkEE
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08-10-2015 12:48 PM
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I should probably preface that I'm new to LabView, and especially new to LabView FPGA so with any luck this is an easy thing that I'm simply overlooking.
I wanted to start with a "simple" example of an FFT on the FPGA working. It seemed to me that the easiest approach is to use the example project "Simple NI-USRP Streaming" and my NI-2942R. This program streams RF data from the antenna, converts to baseband, and streams that (decimated) data to the host which then does the FFT.
All of this is working fine.
But I want to move the FFT to the FPGA side of things, and that's where I run into trouble.
I did find this (http://www.ni.com/white-paper/7088/en/) and I don't see where any problem with my design, except that when I switch to the FFT all I see is 0 instead of data, yet switching back seemingly works fine. The problem is that while I have this example for reading data from the RF side, and there are examples regarding using the FFT, I always get the same result (all 0) when I try to combind the two pieces.
I have attached my Block Diagram VI. Note all my changes corespond with the FFT, the two FIFOs, and the switch between using or bypassing the FFT. Everything else is in the example code.
Thanks for your help!
Solved! Go to Solution.
IronBrotha
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08-11-2015 01:22 PM
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Have you checked the following example?
https://decibel.ni.com/content/docs/DOC-1052
Your Vi is missing some .ctl files.
The best idea woulb be to create a project or a zip file containing all the controls and Vi's.
Warm Regards,
Sigi D
"everything is achieveable through technology'
Solution
Accepted by topic author MinkEE
08-14-2015 04:12 PM - edited 08-14-2015 04:16 PM
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Got it, apparently I missed the "Ready for Input" connection on the bottom of the FFT block. Threw me off since it "built" without it!
Thanks for that example, IronBrotha. While it didn't help with THIS specific problem, it does give me some ideas for my next step which is VERY similiar to that example!
As for the VI, sorry to hear it wasn't complete. I assumed since I didn't add any sub VIs myself to a default example it would just work...but clearly I need to post the entire lvproj file in the future.
