Anemometers may be constructed by a variety of means. I have made them from cups, propellers, and pendulums (hanging and inverted). My favorites are the pendulums for their simplicity and ability to give direction as well as speed. A 2-axis accelerometer gives tilt numbers, is easily calibrated, and is without the need to count pulses. The “X”, “Y” offset ratio makes wind direction clear with near infinite resolution. My first pendulum was inspired by finding an old copper toilet float at a garage sale! Inside I put a Memsic 2125 (http://www.parallax.com) and left it hanging from a gimbal, so that it would not rotate and give erroneous direction. Later, I built one with a transmitter and a compass inside a large plastic egg (16” tall) for my R/C flying club. It was set on a table, or directly on a smooth ceramic floor tile near the runway–though not so accurate it was a sturdy unit that may still be in use today. It took only a moment to calibrate itself and gave accuracy and direction akin to a windsock; the separate display could be located some distance away.