Arduino - Rain Sensor - Buzzer

In this tutorial, We will explore the process of utilizing Arduino for rain detection and creating an alarm system with a buzzer.

Hardware Required

1×Arduino UNO or Genuino UNO
1×USB 2.0 cable type A/B (for USB-A PC)
1×USB 2.0 cable type C/B (for USB-C PC)
1×Rain Sensor
1×Relay
1×12V Active Buzzer
1×12V Power Adapter
1×DC Power Jack
1×Jumper Wires
1×(Recommended) Screw Terminal Block Shield for Arduino Uno
1×(Recommended) Breadboard Shield For Arduino Uno
1×(Recommended) Enclosure For Arduino Uno

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
Please note: These are Amazon affiliate links. If you buy the components through these links, We will get a commission at no extra cost to you. We appreciate it.

About 12V Buzzer and Rain Sensor

If you do not know about 12V buzzer and rain sensor (pinout, how it works, how to program ...), learn about them in the following tutorials:

Wiring Diagram

Arduino Rain Sensor 12V Buzzer Wiring Diagram

This image is created using Fritzing. Click to enlarge image

Arduino Code

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-rain-sensor-buzzer */ #define RAIN_SENSOR_PIN A0 // Arduino pin connected to the OUTPUT pin of rain sensor #define BUZZER_PIN A2 // Arduino pin connected to Buzzer's pin int rain_state = LOW; // current state of rain sensor's pin int prev_rain_state = LOW; // previous state of rain sensor's pin void setup() { Serial.begin(9600); // initialize serial pinMode(RAIN_SENSOR_PIN, INPUT); // set arduino pin to input mode pinMode(BUZZER_PIN, OUTPUT); // set arduino pin to output mode } void loop() { prev_rain_state = rain_state; // store old state rain_state = digitalRead(RAIN_SENSOR_PIN); // read new state if (prev_rain_state == LOW && rain_state == HIGH) { // pin state change: LOW -> HIGH Serial.println("Rain detected!"); digitalWrite(BUZZER_PIN, HIGH); // turn on buzzer } else if (prev_rain_state == HIGH && rain_state == LOW) { // pin state change: HIGH -> LOW Serial.println("Rain stopped!"); digitalWrite(BUZZER_PIN, LOW); // turn off buzzer } }

Quick Steps

  • Connect Arduino to PC via USB cable
  • Open Arduino IDE, select the right board and port
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Move your hand in front of sensor
  • Listen to 12V buzzer's sound

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.

The Best Arduino Starter Kit

※ OUR MESSAGES