Barrier

// Barrier
// Press the button: the barrier (servo) goes up, waits a little, and closes again.

#include <Servo.h>

const int BUTTON_PIN = 2;   // Push button on pin 2 (other side to GND)
const int SERVO_PIN = 9;    // Orange/yellow wire of the servo on pin 9

const int CLOSED = 0;       // Servo angle when the barrier is closed
const int OPEN = 90;        // Servo angle when the barrier is open

Servo barrier;

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  barrier.attach(SERVO_PIN);
  barrier.write(CLOSED);    // Start with the barrier closed
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) { // Button pressed
    // Turn open slowly, degree by degree
    for (int angle = CLOSED; angle <= OPEN; angle++) {
      barrier.write(angle);
      delay(15);
    }
    delay(3000);                        // Open for 3 seconds: the car drives through
    // Slowly close again
    for (int angle = OPEN; angle >= CLOSED; angle--) {
      barrier.write(angle);
      delay(15);
    }
  }
}