Have a look here:
http://www.picbasic.co.uk/forum/show...69&postcount=4
You can use this code to measure the frequency with timer1. This open the timer1 gate for exactly 1 sec. (@4MHz); so you can get a resolution of +- 1Hz. The result return in 2 words Hicntr and Locntr. Obviously you need a routine that convert the 32 bit to decimal.
With a bit less accuracy can be done in pbp.
http://www.picbasic.co.uk/forum/showthread.php?t=7828
Not very easy, but works fine.

Regards
Gianni