What have you got for measuring the wind speed? Rotating cups or a propellor? Or a hinged plate that gets deflected by the wind?
With the former you usually get a pulse output from a slotted disk and optical sensor, feed this through a F to V converter and then a voltage reading display. The latter would simply have a low torque potentiometer at the hinge axix, used as a voltage divider.
If you do NOT have something to measure the wind speed, tackle that first. You'll find this MUCH more difficult than the electronic readout :wink:
Electronic wind speed indicators are not simple projects, especially the mechanical parts , as I found out the hard way. Been through several designs of a rotating cup type until I found a way to seal the tiny ball bearings for reliable roof top operation.
The other problem was how to calibrate that thing once it finally was working. I made a little wind tunnel with a multi speed fan and used a borrowed anemometer. Somebody might suggest doing the calibrations on the back of a moving pickup truck on a windless day. Easier said than done would be my reply.
You can also do it with no moving parts using ultrasonics, there were two articles last year in EPE Magazine, Jan 2003 for just a wind speed indicator, and Aug 2003 for a complete weather station - which uses four ultrasonic transducers to give direction as well as speed.