Re: Detect fundamental Frequency

On Jan 7, 10:09 am, "fredp" <fred...@xxxxxxxxx> wrote:
"fredp" <fred...@xxxxxxxxx> wrote in
news:BrudnfrVXrBToR_anZ2dnUVZ_j6dnZ2d@xxxxxxxxxxxx:

fredp wrote:

Hello All,

I am trying to detect the fundamental frequency of a non-sinusoidal
waveform. I do FFT on the sampled data and I get a bunch of
harmonics.
How
should I go about to detect the fundamental frequency between the
harmonic
signals?

Thank you

Look up definition of "fundamental" and "harmonic".
IOW you didn't ask the question you meant to ask ;)

Thanks Richard,
Well let me try to clear things up. I have got a square waveform. When
I
put it in the frequency domain I get the fundamental frequency and
harmonics ok? Lets say the partial harmonics are greater than the
fundamental component, So the peak fft bin is not related to the
fundamental freq but to the partial one. For example, if a waveform
has
three components at 2,4 and 6 Hz and assume that the 4 hz component is
stronger than 2 hz....

Thanks

For a square wave, why not use some sort of timing approach to estimate
the period instead of dealing with the fft?


sounds like what you need is what we call in the audio/music DSP
world, a "pitch detection algorithm". like AMDF or ASDF or
autocorrelation. (picking the correct extremal points is where the
magic is.)

r b=j

.

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