Design and Analysis of Power Efficient IoT Based Capacitive Sensor System to Measure Soil Moisture

Abstract

With the advancement of new technologies now a days sensors systems have become more intelligent and compact in size as compared to other traditional sensor systems. In this research work, an IoT (Internet of Things) based low cost and power efficient hardware system is presented to monitor soil moisture. A capacitive soil moisture sensor is designed and calibrated in this work. The output data are compared with a standard SEN0193 capacitive soil moisture sensor to check the reliability of the sensor. To make the sensor system a 32 bit ESP32 controller has been used. The controller was programmed according to an algorithm named "Low Threshold Power Optimization (LTPO)" to consume low power. The ESP32 controller has an inbuilt IoT chip that provides more flexibility to the system. A small OLED display is also interfaced with the controller to monitor sensor value directly in the field. In this paper an open source server ThingSpeak.com is used to visualize and store moisture data.