----------
>I'm trying to do a audio spectrum analizer using a 16C73 and the only
>problem I have is how to measure the amplitude of the incoming signal.
>I have to measure the amplitude at 32Hz, 64Hz, 125Hz, 250Hz, 500Hz,
>1000Hz, 2000Hz, 4000Hz, 8000Hz and 16000Hz.
>I don't want to do a separate bandpass filter for each frequency, I just
>want to dos this by software.
>Does any one have any ideas?

Filter the input at slightly higher than 16KHz, sample at slightly higher
than twice the filter frequency, and then run an FFT.  Simple (at least
with a DSP).

>
>Octavio
>--
>
>Octavio Nogueira
>nogueira@mandic.com.br
>http://ourworld.compuserve.com/homepages/tato

-------------------------
Jerry Durand
Durand Interstellar, Inc.
tel:  +1 408 356-3886
fax:  +1 408 356-4659
jdurand@interstellar.com