Obstacle Sensing Robot Using Arduino

Code:

#include <Servo.h>

int ePin=9;
int tPin=8;
int pzoPin=10;
float distance;
long duration;
int servoPin = 11;
Servo Servo1;
int LED=7;

void setup(){
  pinMode(ePin, INPUT);
  pinMode(tPin, OUTPUT);
  Serial.begin(9600);
  pinMode(pzoPin, OUTPUT);
  Servo1.attach(servoPin);
  pinMode(LED, OUTPUT);
}

void loop(){
  Servo1.write(0);
  digitalWrite(LED, HIGH);
  delay(70);
  digitalWrite(LED, LOW);
  delay(2000);
  digitalWrite(tPin, LOW);
  delay(100);
  digitalWrite(tPin, HIGH);
  delay(100);
  digitalWrite(tPin, LOW);
  duration = pulseIn(ePin, HIGH);
  distance=duration/29/2;
  Serial.println("Distance: ");
  Serial.println(distance);
  delay(2);
  if(distance<=52){
    tone(pzoPin, 0, 0);
    delay(100);
    tone(pzoPin, 1000, 500);
    delay(1000);
    Servo1.write(0);
    delay(1000);
    Servo1.write(90);
    delay(1000);
    Servo1.write(0);
    delay(1000);
  }

}

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Circuit Diagram

You Can See It Virtually Working @Tinkercad