Hi Wei,
as Adrian said, sounds like a good job for a block that you write yourself! The GNU Radio
tutorials on https://tutorials.gnuradio.org explain how you can do that :)
I come from a bit of a different perspective on this:
What is the thing you're computing here? I ask because you have "start" AND "stop" tags,
which suggests the amount of samples you are trying to subject to the FFT might be
varying? (Otherwise, you'd just have a "start" tag, and would take the next N samples
after that, N const., I'd assume?).
Note that DFTs of vectors of different length are very hard to compare, and you might want
to be careful with statements you make based on these.
Can you explain what the purpose of this block would be, from a higher level?
Best regards,
Marcus
On 11.11.24 15:34, Huang Wei wrote:
Hello everyone,
For my program, in every 20 ms, I need to choose 60% of data in the stream (I marked them
with stream tags "start" and "stop"), then do FFT and plot, and discard the following 40%.
Is it possible to do all of this in gnuradio with OOT blocks?
I was thinking of keep M in N, but when I look at the block introduction, I am worried
that it may cause inaccuracy due to the changed data interval?
I am also looking at ZMQ sink, to send truncated data to an external Python code for FFT,
but my sample rate is quite high, I am afraid the python code can't handle it.
Please could you guide me in the right direction to do it properly?
Thank you and best regards,
Wei
