Could it be as simple as amplifying into cut off with a transistor or op=20
amp? That should give you a square wave...
watch out for ringing though...
On 4/7/2012 8:21 AM, V G wrote:
> Hi all,
>
> What algorithms/filters/whatever would I start looking into to use a
> microcontroller/FPGA/digital ICs/analog components to detect the frequenc=
y
> of a single audio source such a as an electric guitar input? I don't real=
ly
> even need the actual frequency number, I just somehow need to convert the
> input wave into a square wave/pulse that can be used to pulse an LED, for
> example.
>
> I used my oscilloscope to look at the signal generated by the guitar, and
> it's pretty clean, but it:
>
> 1. doesn't look exactly like a sin wave
> 2. decreases in amplitude over time (and becomes almost exactly like a
> sawtooth wave at low amplitudes)
>
> How would I go about extracting the frequency out of this, or getting a
> clean pulse corresponding to the frequency (like a square wave, or
> whatever)?

--=20
John Ferrell W8CCW
=93During times of universal deceit,
   Telling the TRUTH becomes a revolutionary act=94
      George Orwell


--=20
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