Help in digital filter design

[demonio]

Dear Sirs

First of all, Happy 2008.


I need some help in routines, algorithms in C, C++, etc for filters
FIR or IIR.



Thanks
Fabio Bairros

 

[MooseFET]

Dear Sirs

First of all, Happy 2008.

I need some help in routines, algorithms in C, C++, etc for filters
FIR or IIR.

C++ is a dreadful language and you could be a bit more specific but
I'm sure that if you use the right keywords in google including the
type of filter you want, you will find what you need

Low pass IIR:

y = 0;
for (i=0; i<N; i++) {
y += K * (x-y);
x = y;
}

High pass IIR:

y = 0;
for (i=0; i<N; i++) {
y += K * (x-y);
x -= y;
}

 

[Vladimir Vassilevsky]

I need some help in routines, algorithms in C, C++, etc for filters
FIR or IIR.

L. Thede "Analog and Digital Filter Design Using C"

S. Winder "Analog and Digital Filter Design"

VLV

 

[Tim Wescott]

Dear Sirs

First of all, Happy 2008.


I need some help in routines, algorithms in C, C++, etc for filters FIR
or IIR.



Thanks
Fabio Bairros

Well, that's a vague post.

Do you want paid help, and for someone to get back to you with terms and
rates?

Are you trying to solve some specific problem and want help either
figuring out what filter is best, or how to make a particular filter work
correctly?

More detail from you would elicit better responses from us, I think.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

 

[[email protected]]

I need some help in routines, algorithms in C, C++, etc for filters
FIR or IIR.

Unless you need to recalculate your filter parameters on the fly, the
simplest approach is probably to implement a generic FIR or IIR engine
in C/C++, but provide it with a table of coefficients calculated
according to your needs with a tool like Matlab, Scilab, or maybe
Octave.

 

[MooseFET]

Unless you need to recalculate your filter parameters on the fly, the
simplest approach is probably to implement a generic FIR or IIR engine
in C/C++, but provide it with a table of coefficients calculated
according to your needs with a tool like Matlab, Scilab, or maybe
Octave.

No, the simplest way is to not do it in C but to do it in Octave right
after you work out the constants. This saves a lot of transscibing
between languages.

A good optimizing compiler will remove any multiply by zero steps.

 

[Robert Lacoste]

Dear Sirs

First of all, Happy 2008.

I need some help in routines, algorithms in C, C++, etc for filters
FIR or IIR.

Thanks
Fabio Bairros

Hi Fabio,
If it could help : I have published an introductory article on FIR filters
design and implementation in Circuit Cellar a couple of months ago, with
example code in Scilab and C (Issue 207, october 2007, starting page 70). Cf
www.circuitcellar.com.
Friendly yours,
Robert Lacoste
www.alciom.com