📌 Introduction

Smart Home Automation is a system where different electronic devices and sensors connect to a central controller (Arduino UNO).
This allows your home to become automatic, smart, energy-saving, and more secure.

With Arduino, you can control:

• 🌡 Temperature & humidity (DHT11)
• 🚦 Traffic light simulation
• 🚪 Automatic garage door
• 🏢 Mini elevator system
• 🎯 Motion detection (Radar/PIR)
• 💡 Lights automation
• 💦 Water fountain
• ❄ Air conditioner indicator

This project is perfect for students, DIY makers, and STEM learners.

🧩 Components Needed

✔ Arduino UNO

✔ DHT11 Temperature & Humidity Sensor

✔ PIR Motion Sensor or Radar sensor

✔ Servo Motor (Garage / Elevator)

✔ LEDs (Red/Yellow/Green for traffic light)

✔ Relay Module (to control AC indicator or fountain)

✔ Jumper wires

✔ 5V power

Everything in this project uses low voltage (5V) for safety.

🔌 System Overview From Picture

The system includes:

💡 Lights Automation

Lights turn ON when needed using Arduino control.

❄ Air Conditioner Control (via relay indicator)

Arduino triggers a relay when temperature is high.

🚦 Traffic Light Example

Red, yellow, green LEDs programmed to cycle automatically.

💧 Water Fountain

Controlled by relay based on schedule or button.

🌡 DHT11 Temperature Sensor

Reads room temperature & humidity.

🚪 Garage System

Servo motor or DC motor opens/closes the garage door.

🏢 Elevator Mini System

A small servo simulates elevator up/down movement.

🎯 Radar or PIR Motion

Detects motion and triggers lights or buzzer.

🧾 FULL ARDUINO CODE (All functions combined)

This code includes:

• Traffic light
• Garage door (servo)
• Elevator (servo)
• Motion sensor
• DHT11 temperature & humidity
• Relay control (AC & fountain)

📌 Before uploading: install DHT library
👉 DHT sensor library by Adafruit

#include <DHT.h>
#include <Servo.h>

#define DHTPIN 2
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

// Traffic Light Pins
int redLED = 3;
int yellowLED = 4;
int greenLED = 5;

// Motion Sensor
int motionPin = 6;

// Relay Outputs
int relayAC = 7;
int relayFountain = 8;

// Garage Door Servo
Servo garageServo;

// Elevator Servo
Servo elevatorServo;

void setup() {
  Serial.begin(9600);

  // Traffic light pins
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);

  // Motion sensor
  pinMode(motionPin, INPUT);

  // Relays
  pinMode(relayAC, OUTPUT);
  pinMode(relayFountain, OUTPUT);

  // Servos
  garageServo.attach(9);
  elevatorServo.attach(10);

  // Initialize
  dht.begin();

  garageServo.write(0);      // Garage closed
  elevatorServo.write(90);   // Elevator idle
}

void loop() {
  // -------------------------
  // 1. TRAFFIC LIGHT SYSTEM
  // -------------------------
  digitalWrite(redLED, HIGH);
  delay(3000);
  digitalWrite(redLED, LOW);

  digitalWrite(yellowLED, HIGH);
  delay(1500);
  digitalWrite(yellowLED, LOW);

  digitalWrite(greenLED, HIGH);
  delay(3000);
  digitalWrite(greenLED, LOW);

  // -------------------------
  // 2. READ TEMP & HUMIDITY
  // -------------------------
  float t = dht.readTemperature();
  float h = dht.readHumidity();

  if (!isnan(t)) {
    Serial.print("Temp: ");
    Serial.print(t);
    Serial.print("   Humidity: ");
    Serial.println(h);
  }

  // AC control (relay)
  if (t > 30) {
    digitalWrite(relayAC, HIGH);   // Turn ON AC indicator
  } else {
    digitalWrite(relayAC, LOW);
  }

  // -------------------------
  // 3. MOTION SENSOR AUTOMATION
  // -------------------------
  int motionDetected = digitalRead(motionPin);

  if (motionDetected == HIGH) {
    Serial.println("Motion Detected!");
    digitalWrite(relayFountain, HIGH);  // Turn fountain ON
  } else {
    digitalWrite(relayFountain, LOW);
  }

  // -------------------------
  // 4. GARAGE DOOR
  // -------------------------
  garageServo.write(0);   // Closed
  delay(2000);
  garageServo.write(90);  // Opening half
  delay(2000);
  garageServo.write(180); // Fully open
  delay(2000);

  // -------------------------
  // 5. MINI ELEVATOR
  // -------------------------
  elevatorServo.write(0);    // Down
  delay(2000);
  elevatorServo.write(180);  // Up
  delay(2000);
}

📌 How the Code Works

✔ Traffic Light

Simulates real traffic system using 3 LEDs.

✔ Temperature Control

If temperature > 30°C → AC relay turns ON.

✔ Motion Sensor

Detects movement → activates water fountain.

✔ Garage Door

Servo moves between 0° and 180°.

✔ Elevator

Servo moves up and down.

🔧 Possible Extensions

• Add LCD display
• Use Bluetooth to control via phone
• Add flame or gas sensor
• Add IR remote control
• Add automatic curtains

If you want, I can generate schematic wiring diagrams, PDF file, or PowerPoint version too.

🏷 Hashtags (English + Khmer)

🔧 Tech & Arduino

#Arduino #ArduinoUNO #SmartHome
#HomeAutomation #IOTProject #ArduinoProject
#ElectronicsDIY #STEMProject #CodingProject
#SmartHouse #DHT11 #PIRSensor
#RelayModule #TrafficLightSystem

🇰🇭 Khmer + English

#ឧបករណ៍អេឡិចត្រូនិក #គម្រោងArduino
#ផ្ទះឆ្លាត #បច្ចេកវិទ្យាកម្ពុជា
#រៀនArduino #សិស្សSTEM
#សម័យឌីជីថល #បង្កើតរ៉ូបូត