Increase FFT range(in time) if 2048 samples used in the fourier transform

[Mammu]

When we use 32768 samples in the Audio Spectrum, the FFT mag spectrum is displayed for 50-60 seconds.  whereas if 2048 samples are used, then the FFT mag spectrum displays only for the last 10-15 seconds of the data recording. Can the FFT be displayed for the complete duration of the experiment and not just for the last 10-15 seconds, irrespective of the sample size chosen.

[Jens Noriʇzsɔɥ]

With more samples, it takes longer to collect these for the FFT and correspondingly to fill the buffers for the waterfall diagram. The length is determined by the size of these buffers and the width of the diagram. In the “Audio Spectrum” experiment, there are 256 slots for the frequencies and the overall data size is 32768. So, at most 128 lines are displayed.

Audio is typically recorded at a rate of 44.1 or 48 kHz. In theory, the displayed time span is 128×#samples/48000 (or 44100). In practice, up to 0.05s of data might be discarded and the displayed time span is longer.

If you would like to display the complete duration, you could set the buffer size in https://github.com/phyphox/phyphox-exper...um.phyphox at

Code:

    <container size="32768">tmap</container>
    <container size="32768">fmap</container>
    <container size="32768">fftmap</container>

to 0, i.e. “infinite”.

I am not sure how long phyphox – or the smartphone OS takes this well. The app might crash or be killed…

[Mammu]

Thank you, It worked without any lag.