Sidebar continued ...
 A color organ is a device that
splits music up into numerous
frequency bands and modulates
colored lights (one color of
light per band) according to the
1) Determine the initial set of filter
specifications for the filter you want
2) Run LWDFDesigner inputting these
3) Graph the result to see the resulting
4) If the filter matches your specifications, you are done with the design
phase. If not ...
5) Modify one or more of the filter’s
parameters and/or the design margin
and go back to Step 2 and try again.
as designed, they can be implemented
in a small amount of data and
code space, they use CPU cycles
sparingly, and seem to be stable.
Maybe you can put them to use in
your next project. NV
Once you are satisfied with the
design, it is time to implement the
filter. If you are a C or Java programmer, you can write code that
looks like Listing 1, making sure
you code the correct adapter types
and gamma/alpha values produced
by the design tool. Remember also
it is very important to implement
the top adapters first and get their
execution order correct. If you are
an assembly language programmer,
you can take the alpha values and
run them through Horner.java provided with my article in the September
‘07 issue to get the equations
and/or the code for incorporating
into your filter.
LWDFs are a good choice for
many applications. They are easy to
design, for the most part they function
Contact the Author
Craig Lindley can be contacted via
email at: firstname.lastname@example.org.
November 2007 73