On Mon, 24 Aug 2009 08:09:14 -0500, aamer wrote:

> Hi Friends,
> 
> I am a new bee in embedded systems. My task is to test a filter(low
> pass) with audio in and out connections of hardware board. I have
> developed a low pass filter in C and tested it using goldwave(signal
> processing tool) and need guidance on how to test the same filter with
> audio in and out connections of hardware.
> 
> Thanks in advance.
> Aamer

You've left out a bunch of information.  Do you get to generate the 
signal that's input to the filter?  What's your sampling rate compared to 
the filter's bandwidth?  What are your accuracy requirements?  What are 
the filter imperfections that you're concerned with?

_If_ your sampling rate is generous compared to the filter bandwidth 
(there's not a hard and fast number -- see http://www.wescottdesign.com/
articles/Sampling/sampling.html and consider all your other constraints), 
_if_ you get to generate the filter stimulus, _if_ nonlinearities in the 
filter aren't a big concern, and _if_ you care more about the frequency 
response of the filter than it's impulse response (ringing), then I'd 
suggest injecting a swept-frequency sine wave, and looking at the 
response coming out of the filter.  Then you can build up a Bode plot of 
the filter and compare it to some prototype.  But even then you have to 
know what you're doing if you don't just want an automatic false alarm 
generator, or an automatic "pass all tests" report generator.

-- 
www.wescottdesign.com

Hi Friends,

I am a new bee in embedded systems. My task is to test a filter(low pass)
with audio in and out connections of hardware board. I have developed a low
pass filter in C and tested it using goldwave(signal processing tool) and
need guidance on how to test the same filter with audio in and out
connections of hardware.

Thanks in advance.
Aamer