f-->U converter

[zuckini]

Does a Vi exist to convert a frequency in a voltage signal f-->U converter

[rpursley8]

I don't know of one, but there is a couple ways of doing this. What is your application?

[zuckini]

I became a signal from the soundcart and I want to convert the frequency of this signal to a voltage

[rpursley8]

Some more questions:

1. Is the signal a sinusoid?
2. What is the possible frequency range of the input?
3. Are you trying to process real-time or are you acquiring a block of data and then processing it?

[Sheldon_Stokes]

A super quick and dirty method would be to FFT (or PSD) the signal and look for the peak (use array max for example). This will tell you both the actual value and the bin where the max occurs. The bin index can be converted to actual frequency by knowing the FFT length and sample rate. Then you have a fundamental frequency and can do with that what you want IE: volt = freq * slope + intercept


You'll want to subtract the mean before FFT'ing or you will always get bin 0. Especially if you are using a soundcard where no signal is really at 32768 counts.

Now, my example can be messed up by different waveform issues, but should work for 99.9% of the cases.


Sheldon