Hi Larry,
in addition to what Kim said:
You'll have to consider that what the Qt frequency sink and what a
frequency to voltage converter does are pretty different things:
* The freq-to-volt converter takes a signal and (ideally) gives you a
reading determining the (somehow defined) strongest frequency in
your signal. So it's "one signal over a lot of time in, one number
out", if you want so.
* The Qt frequency sink takes in a period of signal, and shows you all
the frequencies' magnitudes it can detect at once. It's "one signal
over a lot of time in, a set of a lot of frequency magnitudes out".
So the core question is: What do you really want to do, mathematically?
Because I find that highly cool, here's what's happening inside the Qt
frequency sink, even if that might be unrelated to your problem:
* takes in a vector of N samples
* Computes a discrete Fourier transform (using FFTw's fast fourier
transform algorithms) of length N
* computes the square of the magnitude, the logarithm of that,
normalizes each of the N complex result values
* optionally: averages each bin individually
* regularly updates the plot with the N-vector of PSD
Best regards,
Marcus
On 04.11.2015 13:15, larry ho wrote:
>
> Hi
>
>
> I am new to linux and GNU Radio, I am trying to create a frequency to
> voltage converter, I tried looking into the source code of QT GUI
> Frequency Sink to get an idea how it detects frequency. However, it
> seems a little complicated, is there any particular function i should
> look out for in the coding? Or are there any alternative in creating a
> frequency to voltage converter. Greatly appreciative if any advise can
> be provided. Thank you.
>
>
> Regards
>
>
> Larry
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [email protected]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
