Arduino Soil Moisture Sensor Circuit

The arduino soil moisture sensor circuit we will build to read the moisture of soil is shown below.

Arduino soil moisture sensor circuit.

Vcc and ground are how the sensor gets the power it needs to operate. The soil moisture sensor module built around the lm393 comparator gives an active low l level output when the soil is dry determined by a pre setted threshold value. This digital output wet soil l dry soil h is routed to one i o terminal d2 of the arduino microcontroller. Digital mode interfacing arduino and soil moisture sensor to connect the soil moisture sensor fc 28 in the digital mode we will connect the digital output of the sensor to the digital pin of the arduino.

While monitoring the sensor gives us true or false condition with respect to measured moisture content in a soil. If you type in arduino soil moisture sensor into ebay you will see the complete type of sensor needed to build this circuit. Here we connect 3 3v 5v of external power. To connect the soil moisture sensor fc 28 in the digital mode we have to use digital output of the sensor and a digital input of arduino.

This soil moisture sensor circuit is pretty simple. This establishes power for the sensor. All the 16 pins of the pcf8574 driver module are connected with the lcd pins. The sensor has 4 terminals for connection vcc for power gnd analog output and digital output.

The sensor module contains a potentiometer with it which is used to set the threshold value. Let s start with the i2c 16 2 lcd. As you can see the circuit diagram is really simple.