#include <Servo.h>

Servo gate;

int button = PA1;

void setup() {
  pinMode(button, INPUT_PULLUP);

  gate.attach(D5);
  gate.write(0);
}

void loop() {

  if(digitalRead(button) == LOW){
    delay(200);

    gate.write(90);
    delay(3000);

    gate.write(0);
  }
}