Rain Sensor

The rain sensor is used to detect water and it can detect beyond of what a humidity sensor do.

The rain sensor has a built-in potentiometer for sensitivity adjustment of the digital output (D0). It also has a power LED that lights up when the sensor is turned on and a digital output LED.

How does it work?

Basically, the resistance of the collector board varies accordingly to the amount of water on its surface.

When the board is:

• Wet: the resistance increases, and the output voltage decreases
• Dry: the resistance is lower, and the output voltage is higher

 Components Required

• Rain Sensor: FC-37 or YL-83
• Arduino UNO
• Breadboard
• 220 Ohm Resistors
• Red LED
• Green LED
• Jumper wires

Schematics

Code:

/*  Rain sensor Tutorial
 *  www.genbays.com 
 */

int rainPin = A0;
int greenLED = 6;
int redLED = 7;
// you can adjust the threshold value
int thresholdValue = 500;

void setup(){
  pinMode(rainPin, INPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  digitalWrite(greenLED, LOW);
  digitalWrite(redLED, LOW);
  Serial.begin(9600);
}

void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(rainPin);
  Serial.print(sensorValue);
  if(sensorValue < thresholdValue){
    Serial.println(" - It's wet");
    digitalWrite(greenLED, LOW);
    digitalWrite(redLED, HIGH);
  }
  else {
    Serial.println(" - It's dry");
    digitalWrite(greenLED, HIGH);
    digitalWrite(redLED, LOW);
  }
  delay(500);
}

Upload the following sketch to your Arduino board

After Uploading the code start adding drops of water to the collector board.

When the value goes below a certain threshold, a red LED will turn on, and when the value goes above a certain threshold, a green LED will turn on.