but I want to to it in my computer,
I guess serial plotter is not available for this kind of tasks. It only show continuous data which is not approptiate for me.
The serial plotter will show 250 samples before scrolling. So just limit your display to this many samples. You will have a pause between one display and the next as data is gathered and so long as the display is in chunks of 250 samples it will look like a static display as you want. You might have to pad out any short fall with zero values if you do not have enough.Also set the baud rate to the fastest it will go. I used 250000 baud but I think it can go to 500000 baud these days.
In that case, you don't need an Arduino. I don't have the programming skills to do this (at least not without a lot of study) but your computer has a soundcard, and if it's a laptop it also has a microphone. If you have a desktop computer you'll need a microphone, but that's all the hardware you'd need.Your computer also has much more processing power than an Arduino. There are spectrum analyzer applications, or Audacity can analyze the spectrum of a WAV file after you've recorded. But, in most cases those are visual and that may not give you the "raw numbers" you're looking for.MATLAB (and maybe some of the free MATLAB clones) can do FFT on WAV files. I'm not sure if it can read the soundcard in real time.
Can you explain more about limiting the frame
I choose 110k baud rate
I know, serial plotter adds new values to the last column which is not okay for me