Can we program arduino PWM outputs to be non-synchronous
No they are all tied to the processor clock.
Jdoll :- when you say:-
The section on filters is not very accurate.
Do you mean comprehensive or are you saying their are inaccuracies in it. That is there are bits that are wrong?
If so could you be a bit more specific as I would like the opportunity to correct any errors I may have inadvertently made.
As I said, filter design is very complex and deserves at least a book to itself. My main aim was to simplify the concept of a filter so that it didn't get in the way of the main topic of the page which was PWM.
I was involved in the design of active audio filters that went into the U.K.'s nuclear submarines so I do know a bit about the subject. That's not to say my wording might not be right or I made a slip of the calculator.