#include <Servo.h>

Servo myServo;
const int servoPin=38;

void setup() 
{
  myServo.attach(servoPin);
} 

void loop() 
{
  myServo.write(0);
  delay(1000);
  myServo.write(90);
  delay(1000);
  myServo.write(180);
  delay(1000);
}