Pervasive Monitoring in the Context of Precision Agriculture: Using Low-Cost LDR Sensors for Solar Intensity Measurement

In this paper, the architecture of a prototype battery-powered, low-power, IoT weather station is presented. Special attention is paid to the creation of a device easily deployable in a pervasive manner to monitor the microclimate of individual vineyards. The system is based on the LoRaWanprotocol and collects data from a set of sensors to monitor ambient temperature, relative humidity, solar radiation intensity, leaf wetness and amount of liquid precipitation. The presented results are focused only on the measurement of the solar radiation intensity performed using a low-cost CdS LDR sensor. Prolonged field tests are performed deploying five sensor nodes in distinct vineyards of a chosen experimental site. In view of evaluating the photoresistor measurement quality, the measured results are compared with those derived from a properly developed solar radiation simulator and with the ones acquired by a public-available weather station located near the experimental site, demonstrating the good adherence between measured, simulated, and public-available data in different atmospheric conditions.