#include <Arduino.h>  // Include standard Arduino library
#include <Servo.h>    // Include Servo library for controlling servo motors

static const int SERVO_PIN = 9;  // Define pin 9 for the servo signal
Servo myServo;  // Create a Servo object to control the servo motor

void setup(void) {
    myServo.attach(SERVO_PIN);  // Attach the servo to the defined pin
}

void loop(void) {
    myServo.write(0);   // Move servo to 0° position
    delay(1000);        // Wait for 1 second

    myServo.write(90);  // Move servo to 90° position (middle)
    delay(1000);        // Wait for 1 second

    myServo.write(180); // Move servo to 180° position
    delay(1000);        // Wait for 1 second

    myServo.write(90);  // Move servo back to 90° position
    delay(1000);        // Wait for 1 second
}