#include <Wire.h>
#include <LiquidCrystal_I2C.h>

const int trigPin = 5;
const int echoPin = 18;

const int LED1 = 25;
const int LED2 = 26;
const int LED3 = 27;
const int LED4 = 14;

LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);

  lcd.init();
  lcd.backlight();
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  
  long duration = pulseIn(echoPin, HIGH);
  float distance = (duration * 0.0343) / 200; 
 
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distancia: ");
  lcd.print(distance);
  lcd.print(" m");

  
  int ledsOn = 0;
  if (distance >= 1 && distance < 2) {
    digitalWrite(LED1, HIGH);
    ledsOn = 1;
  } else if (distance >= 2 && distance < 3) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    ledsOn = 2;
  } else if (distance >= 3 && distance < 4) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, HIGH);
    ledsOn = 3;
  } else if (distance >= 4) {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, HIGH);
    digitalWrite(LED4, HIGH);
    ledsOn = 4;
  } else {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    digitalWrite(LED4, LOW);
    ledsOn = 0;
  }

  
  lcd.setCursor(0, 1);
  lcd.print("LEDs: ");
  lcd.print(ledsOn);


  Serial.print("Distancia: ");
  Serial.print(distance);
  Serial.print(" m, LEDs encendidos: ");
  Serial.println(ledsOn);

  delay(1000); 
}