#include <LiquidCrystal_I2C.h>

int trigger = 2;
int echo = 3;

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(9600);
  
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
  digitalWrite(trigger, LOW);
  
  lcd.init();
  lcd.backlight();
}

void loop() {

  int dist = ultra();

  if (dist <= 20 || dist > 300) { 
    
    Serial.println("Fuera de Rango");

   
    lcd.clear();
    lcd.setCursor(2, 0);
    lcd.print("UL_FEE_20241");
    lcd.setCursor(1, 1);
    lcd.print("Fuera de Rango");
    delay(1000);   

  } else if (dist <= 35 && dist > 20) { 
    
    Serial.println("Cerca >> Abrir");

    
    lcd.clear();
    lcd.setCursor(2, 0);
    lcd.print("UL_FEE_20241");
    lcd.setCursor(1, 1); 
    lcd.print("Cerca >> Abrir");
    delay(1000);
    
  } else if (dist <= 300 && dist > 35) {
    
    Serial.println("Lejos >> Cerrar");

    
    lcd.clear();           
    lcd.setCursor(2, 0);
    lcd.print("UL_FEE_20241");
    lcd.setCursor(1, 1); 
    lcd.print("Lejos >> Cerrar");
    delay(1000);
  }
}

int ultra() {
  digitalWrite(trigger, HIGH);      
  delayMicroseconds(10);
  digitalWrite(trigger, LOW);
  float t = pulseIn(echo, HIGH);
  float d = t / 59;
  return d;
}