I followed this Wind Speed project:
On the Due, I expected to choose whatever interrupt Pin but found out that using PIN 2 gives totally different results than using PIN 8.
aren't they suppose to be the same on Due?
AFAIk there should not be any difference, both are Schmitt trigger pins (page 12, Sam3x datasheet).
Did you try with pull down resistors on both ?
What is the difference you're seeing? Are you saying you get different wind speed readings depending on which pin is used?