Soil Moisture Sensors Yasaman Sadri, Delaram Keshmiri, Sami Abdelghani Mentor: Fadi Kurdahi This project focuses on the design and development of a Soil Moisture Sensor using the resistive and capacitive methods, which can be used as the main component in a smart irrigation system. A semi-cylindrical shape was used for the design of the capacitor plates in order to maximize the accuracy of the device while keeping the size reasonably small. The new shape was helpful to maximize the contact with the soil, resulting in more linearity in the results. The material used in for the plates of the capacitor was aluminum; the thin aluminum plates were mounted on a PVC pipe. An Arduino UNO and Arduino Pro-Mini was used in this project serving as a microcontroller to generate the signal and also sending control messages to the components in the circuit. The ultimate goal of the project was to deliver Soil Moisture Sensor, which can be used in a smart irrigation system reducing the water consumption level considerably. It was determined that the capacitive sensor works properly at high frequencies (2–3 MHz range) due to the small capacitance value of the sensor (pF range). In order to compare the results with another product obtained by other methods, a resistive soil moisture sensor was designed and developed. The resistive sensor was used to form a complete system with the ability of displaying results on a portable device, serving as the front end sensor to measure the soil moisture level.