// ali kazemi 
//its better to using the external power suplly 
// the angle is determind by the width of PWM  signal
#include <Servo.h>

#define SERVO_PIN 26 

Servo servoMotor;

void setup() {
  servoMotor.attach(SERVO_PIN);  
}

void loop() {
  for (int pos = 0; pos <= 180; pos += 1) {
    servoMotor.write(pos);
    delay(15);
  }
  for (int pos = 180; pos >= 0; pos -= 1) {
    servoMotor.write(pos);
    delay(15); 
  }
}