Arduino Uno is the heart of the system. It requires 5 volts power supply from the USB connection or other regulated power source. Soil moisture sensor is connected to Arduino Uno. Soil moisture sensor gives a resistance variation at the output. That single is applied to the comparator and signal conditioning circuit. The signal conditioning circuit has potentiometer to decide the moisture level above which the output of comparator goes high. That digital signal is given to the Arduino Uno board. If the soil moisture value is above the Threshold level then the motor will be OFF, whereas if the moisture level is low motor will be ON through the relay.