Arduino Rain/Moisture Sensor

Here is a quick and easy rain/moisture sensor made for the Arduino using just a 10k resistor, and two track from a strip board.

In the sketch below it is programmed to light up the built-in LED on pin 13 when wet.

DRY

WET

ARDUINO CODE

/* Flood Sensor

This sketch will light up the LED on Pin 13, when water (anything conductive) bridges the gap in the sensor.

created 02/09/09

*/

const int floodSensors = 2; // the number of the Flood Sensor pin
const int ledPin = 13; // the number of the LED pin

// variables will change:
int floodSensorState = 0; // variable for reading the floodSensors status

void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the flood Sensor pin as an input:
pinMode(floodSensors, INPUT);
}

void loop(){
// read the state of the flood Sensor value:
floodSensorState = digitalRead(floodSensors);

// check if the flood Sensor is wet.
// if it is, the floodSensorState is HIGH:
if (floodSensorState == HIGH) {
// turn LED on:
digitalWrite(ledPin, LOW);
}
else {
// turn LED off:
digitalWrite(ledPin, HIGH);
}
}