Posted on May 17, 2011 at 13:56I am guessing because I can't see how you have put together your program in your development environment.
Look at an example such as ''Hello'' provided with your environment. It probably has another file such as vectors.c with all the interrupt handlers. The unused handlers will simply halt on interrupt. And, there should be a start up file that initializes all the interrupt vectors to call the handlers. You need both of these files (or something equivalent) in your program. Then you modify the TIM3 IRQ Handler to service the interrupt and calculate the frequency.
If this is still a puzzle to you, find someone experienced who can look at your program for errors.
Cheers, Hal
