Looking for a subroutine to check for a fairly regular stream of "on" and "off" inputs to a pin? Want to avoid doing it with interrupts?
I've recently put something together. It isn't well tested yet, but you are welcome to it, if it is of use to you.
It will return, even if there is no pulse train. Actually, it returns the length of a full cycle, but that's inversely proportional to the frequency, isn't it?
Details at....
I hope it is useful to you!
(Developed in connection with the DirtCheapDumbWireless project, DCDWireless.com)