Design and implementation of a capacitive leaf wetness sensor based on capacitance to digital conversion

An innovative implementation of an electronic leaf wetness sensor (LWS) is proposed. It utilizes capacitive sensing, combined with an innovative data acquisition method, which implements a capacitance-to-digital converter. The study explores the design procedure of a capacitive LWS, proposing an analytical approach and emphasizing low manufacturing costs. Since the LWS is intended for Internet of Things (IoT) applications, the paper estimates its energy consumption, introducing a boost regulator to optimize power usage, contributing to extend the battery life. The study presents simulation results and experimental validations, including an ad-hoc calibration procedure in controlled conditions. The sensors were tested in real agricultural environments over a complete vegetative season, demonstrating their capability to operate continuously without problems.