Security Alarm using Arduino and PIR Sensor

Project Overview :

To create a security alarm system that detects unauthorized access or intrusion and alerts the user through audible and/or visual alarms.

Components :

1. Arduino board (such as Arduino Uno)

2. PIR motion sensor module

3. Buzzer or piezo speaker

4. LED (optional for visual indication)

5. Breadboard 

6. Jumper wires

Hardware Setup :

• Connect the PIR motion sensor module to the Arduino. The sensor typically has three pins: VCC, GND, and SIGNAL. Connect VCC to 5V, GND to GND, and SIGNAL to a digital input pin (e.g., pin 2) on the Arduino.

• Connect the buzzer or piezo speaker to the Arduino. Connect one terminal of the buzzer to a digital output pin (e.g., pin 3) on the Arduino and the other terminal to GND.

• Optionally, connect an LED to a digital output pin (e.g., pin 4) on the Arduino for visual indication.

Software Setup : 

Arduino Code :

#define PIR_PIN 2 // Digital pin connected to PIR sensor
#define BUZZER_PIN 3 // Digital pin connected to buzzer
#define LED_PIN 4 // Digital pin connected to LED (optional)
void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  
  Serial.begin(9600);
  Serial.println("Security Alarm System - Ready");
}
void loop() {
  int motionDetected = digitalRead(PIR_PIN);
  
  if (motionDetected == HIGH) {
    digitalWrite(BUZZER_PIN, HIGH); // Activate the buzzer
    digitalWrite(LED_PIN, HIGH); // Turn on the LED (optional)
    Serial.println("Intruder Detected - Alarm Activated!");
    delay(5000); // Alarm duration (adjust as needed)
    digitalWrite(BUZZER_PIN, LOW); // Deactivate the buzzer
    digitalWrite(LED_PIN, LOW); // Turn off the LED (optional)
  }
}

Code File : Click Here

Project Outcome:

The completed security alarm system provides effective protection against unauthorized access or intrusion, alerting users to potential security threats through audible and/or visual alarms. With its customizable features and robust functionality, the system enhances the security and peace of mind of users in various environments.

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