Obstacle_Avoider_Robot_Servo_Sunil_Singh_Negi

 #include <Servo.h> 

Servo Myservo;

#define trigPin 9           // Trig Pin Of HC-SR04

#define echoPin 8        // Echo Pin Of HC-SR04

#define MLa 4                   //left motor 1st pin IN1

#define MLb 5                  //left motor 2nd pin IN2

#define MRa 6               //right motor 1st pin  IN3

#define MRb 7               //right motor 2nd pin  IN4

long duration, distance;

void setup() {

  Serial.begin(9600);

  pinMode(MLa, OUTPUT);     // Set Motor Pins As O/P

  pinMode(MLb, OUTPUT);

  pinMode(MRa, OUTPUT);

  pinMode(MRb, OUTPUT);

  pinMode(trigPin, OUTPUT);       // Set Trig Pin As O/P To Transmit Waves

  pinMode(echoPin, INPUT);        //Set Echo Pin As I/P To Receive Reflected Waves

  Myservo.attach(10);

}

void loop() 

{

  Serial.begin(9600);

  digitalWrite(trigPin, LOW);

  delayMicroseconds(2);   

  digitalWrite(trigPin, HIGH);       // Transmit Waves For 10us

  delayMicroseconds(10);

  duration = pulseIn(echoPin, HIGH);        // Receive Reflected Waves

  distance = duration / 58.2;                       // Get Distance

  Serial.println(distance);

  delay(10);

  if (distance > 15)               // Condition For Absence Of Obstacle            

  {

    Myservo.write(90);

    digitalWrite(MRb, HIGH);       // Move Forward

    digitalWrite(MRa, LOW);

    digitalWrite(MLb, HIGH);                                

    digitalWrite(MLa, LOW);                                                       

  }

  else if ((distance < 10)&&(distance > 0))            // Condition For Presence Of Obstacle

  {

    digitalWrite(MRb, LOW);     //Stop                

    digitalWrite(MRa, LOW);

    digitalWrite(MLb, LOW);                                

    digitalWrite(MLa, LOW);

    delay(100);

    

    Myservo.write(0);

    delay(500);

    Myservo.write(180);

    delay(500);

    Myservo.write(90);

    delay(500);

    

    digitalWrite(MRb, LOW);     // Move Backward             

    digitalWrite(MRa, HIGH);

    digitalWrite(MLb, LOW);                                

    digitalWrite(MLa, HIGH);

    delay(500);

    digitalWrite(MRb, LOW);        //Stop                

    digitalWrite(MRa, LOW);

    digitalWrite(MLb, LOW);                                

    digitalWrite(MLa, LOW);  

    delay(100);  

    digitalWrite(MRb, HIGH);     // Move Left     

    digitalWrite(MRa, LOW);   

    digitalWrite(MLa, LOW);                                 

    digitalWrite(MLb, LOW);  

    delay(500);

  }

}