Barometer is an instrument for determining the pressure of the atmosphere and hence for assisting in forecasting weather. Pressure tendency can forecast short term changes in the weather. A device that shows a tendency change in atmospheric pressure in a unit of time is called Tendencymeter. The video describes how to make such a device with the help of Arduino microcontroller and 9g servo motor, which serves as a pointer.
Read DIY Simple Weather Forecast Device via Hackster
An interesting link found among my daily reading