It seems like DIY weather stations are everywhere, and while most can perform the basic functions of measuring temperature, humidity, and air pressure, the majority are still unable to determine wind speed and direction. In response, Austin Allen from Elation Sports Technologies LLC created his own system that uses an anemometer and weathervane to measure the wind.
Both the wind direction sensor and wind speed sensor were secured to sections of EMT conduit with 3D-printed mounts. The speed sensor utilizes a series of internal photo interrupters which get blocked by small plastic tabs whenever the disc spins. By reading the resulting analog voltage output, the connected Arduino Nano can map the value to a speed. The directions sensor uses a single Hall effect sensor combined with a polarized magnet in order to determine the orientation of the resulting magnetic field.
Once every 0.8 seconds, the Arduino takes a reading from the two wind sensors and sends that data over USB to a host PC where a Python script collects and writes it to a CSV file. This newly-gathered information can then be converted into actual speed and directional values, which can be plotted with the help of a graphing utility.
To read more about this project, you can check out Allen’s blog post here.