As you can see the circuit diagram is really simple.
Arduino soil moisture sensor circuit.
We connect vcc to 5v on the arduino board and gnd to gnd on the arduino.
If you type in arduino soil moisture sensor into ebay you will see the complete type of sensor needed to build this circuit.
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.
Vcc and ground are how the sensor gets the power it needs to operate.
The sensor has 4 terminals for connection vcc for power gnd analog output and digital output.
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.
All the 16 pins of the pcf8574 driver module are connected with the lcd pins.
Let s start with the i2c 16 2 lcd.
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 establishes power for the sensor.
This soil moisture sensor circuit is pretty simple.
Here we connect 3 3v 5v of external power.
The arduino soil moisture sensor circuit we will build to read the moisture of soil is shown below.
We can adjust the threshold using the potentiometer in the sensor.
This digital output wet soil l dry soil h is routed to one i o terminal d2 of the arduino microcontroller.