Vavuud is a simple, plastic wind meter for your smartphone that takes advantage of magnetic power in order to give you an accurate wind reading. It plugs into your phone’s jack and relays the information to you via a simple app. Here’s how it works:
As its arms spin in the breeze, the magnetometer in your phone detects the field created by the two magnets embedded in the Vaavud’s rotor. The app then converts the rotations of these magnets into wind speed using modified sound processing algorithms.