What It Does (Yeh Kya Karta Hai?)

Yeh Radar lagataar left-right scan karega.

• Normal Mode: Servo ghoomti rahegi aur area scan karegi.
• Intruder Detected: Agar koi cheez 20cm ke range mein aayi, to Servo usi angle par ruk jayegi aur Buzzer “Beep-Beep” karega (Target Locked

Components Required

• Microcontroller: Arduino Uno
• Servo Motor (SG90)
• Ultrasonic Sensor (HC-SR04)
• Buzzer (Active)
• Breadboard & Jumper Wires

Wiring (Taarein Jorna)

Servo Motor:

• Orange Wire ➡️ Pin 9
• Red Wire ➡️ 5V
• Brown Wire ➡️ GND

Buzzer:

• Long Leg (+) -> Pin 8
• Short Leg (-) -> GND

Ultrasonic Sensor:

• Trig ➡️ Pin 10
• Echo ➡️ Pin 11
• VCC ➡️ 5V
• GND ➡️ GND

Code

// PlzPapa Project #21: Smart Radar with Intruder Alert
// Scan karega, aur chor ko dekh kar ruk jayega!

#include <Servo.h>

Servo myServo;
int trigPin = 10;
int echoPin = 11;
int buzzerPin = 8;

// Kitnay faaslay par alert ho? (20 cm)
int range = 20; 

void setup() {
  myServo.attach(9);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);
}

// Distance napnay ka function
int calculateDistance() {
  digitalWrite(trigPin, LOW); delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  // --- Right taraf Scan (15 se 165 degree) ---
  for(int i=15; i<=165; i++) {  
    myServo.write(i);
    delay(30); // Speed control
    
    int dist = calculateDistance();
    
    // Agar koi range mein aa gaya
    if (dist < range && dist > 0) {
      // 1. Ruk jao aur Alarm bajao
      digitalWrite(buzzerPin, HIGH); // Shor machao
      delay(100);
      digitalWrite(buzzerPin, LOW);
      delay(100);
      
      // 2. Loop ko yahin roka rakhain jab tak cheez samnay hai
      // (Optional: Agar aap chahte hain ke lock rahe)
      while(calculateDistance() < range) {
         digitalWrite(buzzerPin, HIGH);
         delay(200);
         digitalWrite(buzzerPin, LOW);
         delay(200);
      }
    }
  }

  // --- Wapis Left taraf Scan (165 se 15 degree) ---
  for(int i=165; i>15; i--) {  
    myServo.write(i);
    delay(30);
    
    int dist = calculateDistance();
    
    if (dist < range && dist > 0) {
       digitalWrite(buzzerPin, HIGH);
       delay(100);
       digitalWrite(buzzerPin, LOW);
       delay(100);
       
       while(calculateDistance() < range) {
         digitalWrite(buzzerPin, HIGH);
         delay(200);
         digitalWrite(buzzerPin, LOW);
         delay(200);
      }
    }
  }
}

Kaise Test Karein?

1. Code upload karein.
2. Radar ghoomna shuru karega.
3. Apna haath Radar ke samnay layen.
4. Radar ruk jayega aur Buzzer bajna shuru ho jayega.
5. Haath hatayen, Radar wapis ghoomna shuru kar dega.