While advocating the use of reciprocal method to measure low frequencies - one warning has to be made : If due to some reason the second edge of the pulse is missed, then the counter waits for it eternally ( a.k.a MCU hangs ). This pitfall needs to be addressed.

And Vivek still maintains,
"I tried using the counter, but i get 1 Hz accuracy, i am looking at .01 Hz accuracy."

While it kind of conveys the message, I think he wants 0.01Hz resolution.


Raghu