Arduino program to interface soil moisture sensor

Interfacing a soil moisture sensor with an Arduino involves reading the analog values from the sensor and displaying the readings. Here is a simple Arduino program to do that:

Hardware Required:

Arduino board (e.g., Uno)
Soil moisture sensor
Breadboard and jumper wires

Connections:

Connect the VCC pin of the soil moisture sensor to the 5V pin of the Arduino.
Connect the GND pin of the sensor to the GND pin of the Arduino.
Connect the analog output pin (usually labeled A0 or AO) of the sensor to an analog input pin on the Arduino (e.g., A0).

Solution

// C++ code
//
int moisture = 0;

void setup()
{
  pinMode(A0, OUTPUT);
  pinMode(A1, INPUT);
  Serial.begin(9600);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
}

void loop()
{
  // Apply power to the soil moisture sensor
  digitalWrite(A0, HIGH);
  delay(10); // Wait for 10 millisecond(s)
  moisture = analogRead(A1);
  // Turn off the sensor to reduce metal corrosion
  // over time
  digitalWrite(A0, LOW);
  Serial.println(moisture);
  digitalWrite(8, LOW);
  digitalWrite(9, LOW);
  digitalWrite(10, LOW);
  digitalWrite(11, LOW);
  digitalWrite(12, LOW);
  if (moisture < 200) 
  {
  	digitalWrite(12, HIGH);
  } 
  else if (moisture < 400) 
  {
      digitalWrite(11, HIGH);
  } 
  else if (moisture < 600) 
  {
        digitalWrite(10, HIGH);
  } 
  else if (moisture < 800) 
  {
       digitalWrite(9, HIGH);
  }
  else 
  {
      digitalWrite(8, HIGH);
  }
  
  delay(100); // Wait for 100 millisecond(s)
}

▶ RUN

Output/ Explanation:

O Level Online Exam

Programming Examples

Arduino program to interface soil moisture sensor