// C++ code
// 
#include<Servo.h> 
Servo myservo; 
#define obstacle 10
int detect=LOW; 
int pos=0; 
void setup()
{ 
  Serial.begin(9600); 
    pinMode(obstacle,INPUT); 
      myservo.attach(9);
      }

      void loop()
      { 
        detect=digitalRead(obstacle); 
          if(detect==HIGH) 
            { 
                Serial.println("obstacle deteced"); 
                    for(pos=0;pos<=180;pos+=1) 
                        { 
                              myservo.write(pos); 
                                    delay(5);
                                        } 
                                          } 
                                            else   
                                              {
                                                  Serial.println("no obstacle deteced"); 
                                                      for(pos=180;pos>=0;pos-=1) 
                                                          { 
                                                                myservo.write(pos); 
                                                                      delay(5);
                                                                          }  
                                                                            } 
                                                                              delay(200);
                                                                                  
                                                                                  }