Quote Originally Posted by mister_e
Yup but 100 Ohm is probably too low. 6 Vac gives about 9Volts in Peak. 9/100=90ma... i'll prefer to use something like an 1K.

Probably the following post i did few times ago can help. It's a simple frequency counter.
http://www.picbasic.co.uk/forum/showthread.php?t=1044

Cool thanks, i noticed you simply used a 1k on the in and a 10k to ground?

basically i'm using a 6v peak to peak 60hz signal just need zero crossing