Published March 5, 2026 © MIT

IoT Smart Door Lock (Mobile Controlled)

An IoT-based smart door lock that lets you securely lock and unlock your door directly from your mobile phone. 🔐📱

BeginnerFull instructions provided8 hours170

Things used in this project

Software apps and online services

Arduino IDE

Story

🌍 1️⃣ Introduction

Aaj ke modern homes me security aur convenience dono important hai. Traditional door locks me kuch limitations hoti hain:

❌ Key lost ho jati hai❌ Remote access nahi❌ Access log nahi❌ Smart home integration nahi

In problems ko solve karne ke liye maine design kiya:

🔐 Smart Door Lock System (Mobile Controlled)

🔐 Smart Door Lock System (Mobile Controlled)

Ye system smartphone se door lock/unlock karne ki facility deta hai.

💡 2️⃣ System Overview

Smart Door Lock system:

✔ Mobile se lock/unlock✔ WiFi control✔ Real-time door status✔ Remote access✔ Smart home integration

🧰 3️⃣ Required Hardware

3.1️⃣ ESP32 (Main Controller)

Use:Main controller jo WiFi communication aur door lock control karta hai.

3.2️⃣ Servo Motor (Door Lock Mechanism)

Use:Door lock ko physically rotate karke lock/unlock karta hai.

3.3️⃣ Magnetic Door Sensor

Use:Door open/close detect karta hai.

3.4️⃣ Relay Module (Optional)

Use:High power electronic lock control ke liye.

3.5️⃣ 5V Power Supply

Use:ESP32 aur servo motor ko stable power supply deta hai.

🔌 4️⃣ Circuit Diagram

🔗 5️⃣ Wiring Table

Servo Motor → ESP32

Red → 5VBrown → GNDOrange → GPIO 18

Magnetic Sensor → ESP32

One wire → GPIO 4Other wire → GND

💻 6️⃣ Software Used

1️⃣ Arduino IDE2️⃣ ESP32 Board Package3️⃣ WiFi Library4️⃣ MQTT / HTTP API5️⃣ Android App / Web Dashboard

⚙️ 7️⃣ Working Logic

1️⃣ User mobile app se command bhejta hai2️⃣ WiFi ke through ESP32 command receive karta hai3️⃣ Servo motor rotate hota hai4️⃣ Door lock/unlock ho jata hai5️⃣ Door status cloud par update hota hai

🚀 8️⃣ Key Features

✔ Mobile controlled door lock✔ Remote access✔ Smart home ready✔ Door status monitoring✔ Low cost IoT solution

🏠 9️⃣ Applications

✔ Smart homes✔ Offices✔ Hotels✔ Rental rooms✔ Hostels

📈 🔎 SEO Keywords (Hackster Friendly)

Smart door lock projectESP32 smart door lockIoT door lock systemMobile controlled door lockWiFi smart lock ESP32Smart home lock project

📞 🔧 Project Support

Complete project, customization, PCB design & deployment available.

📲 WhatsApp: +91 9336183481

🏁 Conclusion

Smart Door Lock system provides:

✔ Convenience✔ Security✔ Remote control✔ Smart home integration

🔐 Control your door from anywhere with IoT.

Complete ESP32 Code

#include <WiFi.h>
#include <ESP32Servo.h>
#include <WebServer.h>

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

// Create Web Server
WebServer server(80);

// Servo Pin
#define SERVO_PIN 18

// Door Sensor Pin
#define DOOR_SENSOR 4

Servo lockServo;

// Lock Positions
int lockPos = 0;
int unlockPos = 90;

String doorState = "Locked";


// ----------------------
// Lock Door Function
// ----------------------
void lockDoor() {
  lockServo.write(lockPos);
  doorState = "Locked";
  server.send(200, "text/plain", "Door Locked");
}


// ----------------------
// Unlock Door Function
// ----------------------
void unlockDoor() {
  lockServo.write(unlockPos);
  doorState = "Unlocked";
  server.send(200, "text/plain", "Door Unlocked");
}


// ----------------------
// Status Function
// ----------------------
void getStatus() {

  int sensor = digitalRead(DOOR_SENSOR);

  String status = "Door: " + doorState;

  if(sensor == LOW) {
    status += " (Closed)";
  } else {
    status += " (Open)";
  }

  server.send(200, "text/plain", status);
}


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

  Serial.begin(115200);

  pinMode(DOOR_SENSOR, INPUT_PULLUP);

  lockServo.attach(SERVO_PIN);
  lockServo.write(lockPos);

  WiFi.begin(ssid, password);

  Serial.println("Connecting to WiFi...");

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

  Serial.println("");
  Serial.println("WiFi Connected");
  Serial.println(WiFi.localIP());


  // API Routes
  server.on("/lock", lockDoor);
  server.on("/unlock", unlockDoor);
  server.on("/status", getStatus);

  server.begin();
}


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

  server.handleClient();

}