How does work Soil hygrometer sensor with an Arduino Nano board?

Hello guys, Welcome back to another article from the SriTu Hobby. Today we are going to talk about the Soil Moisture Sensor. Let us first learn what is a soil moisture sensor. We can mainly use it to measure soil moisture. Also, the irrigation system can be easily designed using this sensor. Through it, the moisture in the soil can be monitored and the water system can be properly controlled. This sensor consists of two main parts. We identify the two parts separately.

The Probe

This is in the form of a fork and should be inserted into the soil. We will learn later how the probe works.

The Module

This is designed to be attached to the Arduino board. For this, the module includes an analog PIN and a digital PIN. The main function of this module is to generate the output voltage according to the resistance value received through the probe. We can get it as a signal from Analog and Digital pins. Also, the Potentiometer here can change the sensitivity of the digital value. Also here we can see four pins. The work done by them is given below.

• VCC     –         supply voltage (5v)
• GND     –         The GND connection of the module
• AO         –        Analog output. From this pin, we can get a value of 0 – 1024. We need to connect this                            PIN to an analog PIN on the Arduino board.
• DO         –        Digital output. We can get a value of 1 or 0. We need to connect this PIN to a digital                                PIN on the Arduino board.

Let’s see how this sensor works

The test part(Probe) of this sensor is designed to include two conductors. Also, these two conductors act as a variable resistor. This resistance is inversely proportional to the moisture content of the soil. As the amount of water in the soil increases, the conductivity increases and less resistance occurs. Also, as the amount of water in the soil decreases, the conductivity decreases and more resistance occurs. This resistor produces an output voltage and we can measure the moisture by measuring it. That task is performed by the module.

OK, now we will test how this sensor works with Arduino. The necessary accessories are given below. You can easily buy these components using the links below.

• Arduino Nano board x 1 — Our Store / Amazon
• Soil moisture sensor x 1 — Our Store / Amazon
• Breadboard x 1 — Our Store / Amazon 
• Jumper wires —  Our Store / Amazon 

Disclosure: These Amazon links are Affiliate links. As an Amazon Associate, I earn from qualifying purchases.

OK, let’s do it step by step.

Step 1

Firstly, identify these components.

Step 2

Secondly, connect these components. For that, use the following circuit diagram.

Step 3

Thirdly, let’s create the required program for this project. The required program is given below.

• The complete program of this project – Download

/*How to work soil hydrometer moisture sensor.
  Serial monitor readings.
  created by the SriTu Tech team.
  Read the code below and use it for any of your creation
*/
 
void setup() {
  Serial.begin(9600);//enable serial monitor
}
 
void loop() {
  int value = analogRead(A1);//read value
  Serial.print("Moisture value : ");//print text
  Serial.println(value);//print value
}

Code explanation 

In the void setup, the Serial monitor is enabled.

void setup() {
  Serial.begin(9600);//enable serial monitor
}

In the void loop, the sensor values are obtained and those values are put into the integer variable. Finally, the values are displayed on the serial monitor.

void loop() {
  int value = analogRead(A1);//read value
  Serial.print(“Moisture value : “);//print text
  Serial.println(value);//print value
} 

Step 4

Now, select the board and port. After, click the upload button.

OK, now you can test this tutorial. The full video guide is below. So, we will meet in the next tutorial. Have a good day.

How does work Soil hygrometer sensor with an Arduino Nano board?