Скачать или смотреть Arduino PIR Motion Sensor + LED + Buzzer | Smart Security System (2 of 5)

In this Arduino tutorial, we continue building our Smart Security System by adding a piezo buzzer. Now when motion is detected, the system not only lights up an LED but also sounds an audible alert. This project builds on Stage 1 and introduces basic sound output using a buzzer.

Parts Used
Arduino Uno
PIR Motion Sensor
LED
220Ω resistor
Piezo buzzer
Breadboard
Jumper wires

Recommended Kits & Accessories
Most Arduino Starter Kits include the components used here—plus extras to keep you experimenting.
Starter Kit: https://amzn.to/4mz7OqJ
Project Book: https://amzn.to/3V5WBlr
Apparel: https://amzn.to/4mRekt7

Series Mention
📚 This project is part of a full tutorial series and upcoming book!
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Code:
const int pirPin = 2; // PIR sensor output connected to digital pin 2
const int ledPin = 13; // LED connected to digital pin 13
const int buzzerPin = 8; // Piezo buzzer connected to digital pin 8

void setup() {
pinMode(pirPin, INPUT); // Set PIR sensor pin as input
pinMode(ledPin, OUTPUT); // Set LED pin as output
pinMode(buzzerPin, OUTPUT); // Set buzzer pin as output
Serial.begin(9600); // Initialize serial communication at 9600 baud
}

void loop() {
int motion = digitalRead(pirPin); // Read the signal from PIR sensor

if (motion == HIGH) { // If motion is detected
digitalWrite(ledPin, HIGH); // Turn on LED
digitalWrite(buzzerPin, HIGH); // Activate buzzer
delay(200); // Wait for 200 milliseconds
digitalWrite(ledPin, LOW); // Turn off LED
digitalWrite(buzzerPin, LOW); // Deactivate buzzer
delay(200); // Wait for 200 milliseconds
Serial.println("Motion detected!"); // Print message to serial monitor
} else {
digitalWrite(ledPin, LOW); // Ensure LED is off
digitalWrite(buzzerPin, LOW); // Ensure buzzer is off
}

delay(100); // Short delay before next reading
Serial.println("No motion"); // Print message to serial monitor
}