Re: Low pass filter on a PIC

"Manfred" <mmornhin@[EMAIL PROTECTED]
> wrote in 
news:orKdnemiBNUqVHPVnZ2dnUVZ_hudnZ2d@[EMAIL PROTECTED]
> The only thing I can come up with is averaging the last several samples,
> perhaps with some weighing. But there must be some better method!

That's pretty much the answer.  You can choose ideal weightings according 
to what your goals are, but a moving average is what things come down to.

One caveat is that unless you're a bit careful, using timer interrupts and

the like to trigger your sampling, you could have a good deal of jitter in

your sample rate, and the math behind the low pass filter can get pretty 
complicated.  You'll still be "low pass", but you'll have problems 
characterizing the filter.

Another caveat is that you'll probably find yourself implementing the 
filter with integer math, and if you're not used to that, you could get 
yourself in a bit of a mess.

-- 
Scott
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