#include <Servo.h> 

int led = 13;

Servo myservo;  // create servo object to control a servo 
                // twelve servo objects can be created on most boards
 
int pos = 0;    // variable to store the servo position 
 
void setup() 
{ 
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object 
} 
 
void loop() 
{ 
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second
  
  for(pos = 0; pos <= 180; pos += 1) // goes from 0 degrees to 180 degrees 
  {                                  // in steps of 1 degree 
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
  for(pos = 180; pos>=0; pos-=1)     // goes from 180 degrees to 0 degrees 
  {                                
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
}