Arduino Anemometer on the cheap?

madepablo, I am not sure what meant by:-

Okay, coming back to the anemometer

After my post. It was a link to my anemometer I posted.

Many of these were made at the time. I even heard of one being calibrated in the wind tunnel of British Aerospace. Several hundred were made and I got lots of good feedback. It was very low cost and used just on opto slot detector. I even sold on to a person in Greenland!
I don't sell the bits any more but it uses the system of brass tubes and rods you get in model shops.