//https://learn.adafruit.com/multi-tasking-the-arduino-part-1/ditch-the-delay

  1. include <Servo.h>

// Pin 13 has an LED connected on most Arduino boards. // give it a name: 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 
  } 

}