Development of an Automatic Weather Station for Irrigation Management via IoT

Water is a critical resource in irrigated agriculture, and its efficient management, based on water balance and meteorological data, requires data collection and transmission systems with high reliability and the capacity to accurately represent the physical phenomena occurring in the agricultural environment. Thus, aiming to manage irrigation using smart devices, this article presents the development of the hardware and software of a complete automatic meteorological station based on IoT, from the calibration of the sensor elements, to the development of the final device, which operates with the routine of reading variables at intervals of 10 s, followed by online storage of average and extreme data every 10 min, followed by estimation of daily evapotranspiration using the Penman–Monteith method. The device has a user communication interface via a messaging application, through which the current weather condition can be requested remotely and receive daily data collected. The final version had its operation analyzed continuously, for a period of one year, together with a commercial automatic station, where a correlation was found between its estimates (R²) of evapotranspiration of 0.93, together with an average absolute error of 0.30 mm, obtaining an excellent classification in the capacity to estimate evapotranspiration.