Published March 2, 2026 © MIT

IoT-Based Smart Door Security System

An IoT-based smart door security system that detects intrusions instantly and sends real-time alerts for enhanced home safety. 🔐📡

BeginnerFull instructions provided8 hours618

Things used in this project

Software apps and online services

Arduino IDE

Story

🌍 1️⃣ Introduction

Aaj ke time me home security sabse important concern hai:

Unauthorized entry

Unauthorized entry

Door break attempt

Door break attempt

Ghar me koi nahi ho to risk

Ghar me koi nahi ho to risk

CCTV hone ke baad bhi instant alert nahi

CCTV hone ke baad bhi instant alert nahi

Traditional lock systems:

❌ Manual❌ No remote monitoring❌ No real-time alert

Isliye maine design kiya:

🔐 Smart Door Security System

🔐 Smart Door Security System

Ek IoT-based intelligent security solution jo intrusion detect karta hai aur turant alert bhejta hai.

💡 2️⃣ System Overview

✔ Magnetic door sensor monitoring✔ PIR motion detection✔ Buzzer alarm✔ WiFi real-time notification✔ Access log system

🧰 3️⃣ Required Hardware

3.1️⃣ ESP32 (Main Controller)

Use: Main controller + WiFi communication.

3.2️⃣ Magnetic Door Sensor (Reed Switch)

Use: Door open/close detection.

3.3️⃣ PIR Motion Sensor

Use: Motion detection near door.

3.4️⃣ Buzzer

Use: Local alarm alert.

3.5️⃣ 5V SMPS Power Supply

Use: Stable power supply.

🔌 4️⃣ Circuit Diagram

🔗 5️⃣ Wiring Table

Magnetic Sensor → ESP32

One wire → GPIO 4Other wire → GND

PIR Sensor → ESP32

VCC → 5VGND → GNDOUT → GPIO 5

Buzzer → GPIO 18

⚙️ 6️⃣ Working Logic

1️⃣ Door closed → Normal state2️⃣ Door open → Alert trigger3️⃣ PIR detect motion → Intrusion alert4️⃣ Buzzer ON5️⃣ WiFi notification sent6️⃣ Event log update

🚀 7️⃣ Key Features

✔ Real-time door monitoring✔ Intrusion detection✔ WiFi alert system✔ Local alarm✔ Expandable to smart lock

🏠 8️⃣ Applications

✔ Smart home security✔ Shops✔ Offices✔ Warehouses✔ Hostels

📈 9️⃣ SEO Keywords

Smart door security systemESP32 home security projectIoT door intrusion alertWiFi door alarm systemReed switch door monitoringSmart home security ESP32

📞 1️⃣0️⃣ Project Support

Complete project, customization, PCB design & deployment available.

📲 WhatsApp: +91 9336183481

🏁 1️⃣1️⃣ Conclusion

Smart Door Security System ensures:

✔ Real-time protection✔ Remote monitoring✔ Instant intrusion alert✔ Smart home ready solution

Secure your home the smart way 🔐🚪

🔐 IoT-Based Smart Door Security System ✅ Complete ESP32 Code

#include <WiFi.h>
#include <PubSubClient.h>

// ----------------------
// Pin Configuration
// ----------------------
#define DOOR_SENSOR 4     // Magnetic reed switch
#define PIR_SENSOR 5      // Motion sensor
#define BUZZER 18         // Alarm buzzer

// ----------------------
// WiFi Credentials
// ----------------------
const char* ssid = "YOUR_WIFI_NAME";
const char* password = "YOUR_WIFI_PASSWORD";

// ----------------------
// MQTT Configuration
// ----------------------
const char* mqtt_server = "broker.hivemq.com";
const char* topic_alert = "smartdoor/alert";
const char* topic_status = "smartdoor/status";

WiFiClient espClient;
PubSubClient client(espClient);

// ----------------------
// Variables
// ----------------------
bool lastDoorState = HIGH;
bool alarmTriggered = false;

// ----------------------
// WiFi Setup
// ----------------------
void setup_wifi() {
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi Connected");
}

// ----------------------
// MQTT Reconnect
// ----------------------
void reconnect() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    if (client.connect("SmartDoorClient")) {
      Serial.println("MQTT Connected");
    } else {
      delay(2000);
    }
  }
}

// ----------------------
// Setup Function
// ----------------------
void setup() {

  Serial.begin(115200);

  pinMode(DOOR_SENSOR, INPUT_PULLUP);
  pinMode(PIR_SENSOR, INPUT);
  pinMode(BUZZER, OUTPUT);

  digitalWrite(BUZZER, LOW);

  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

// ----------------------
// Main Loop
// ----------------------
void loop() {

  if (!client.connected()) {
    reconnect();
  }

  client.loop();

  bool doorState = digitalRead(DOOR_SENSOR);
  bool motionState = digitalRead(PIR_SENSOR);

  // Door Open Detection
  if (doorState == LOW && lastDoorState == HIGH) {
    Serial.println("🚪 Door Opened!");
    client.publish(topic_alert, "Door Opened");
    digitalWrite(BUZZER, HIGH);
    alarmTriggered = true;
  }

  // Motion Detection
  if (motionState == HIGH) {
    Serial.println("🚨 Motion Detected!");
    client.publish(topic_alert, "Motion Detected");
    digitalWrite(BUZZER, HIGH);
    alarmTriggered = true;
  }

  // Reset Alarm after 5 seconds
  if (alarmTriggered) {
    delay(5000);
    digitalWrite(BUZZER, LOW);
    alarmTriggered = false;
  }

  lastDoorState = doorState;

  delay(500);
}