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

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

const int led1 = 14; 
const int led2 = 25;
const int led3 = 26;
const int led4 = 27;

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)/2;

  apagarLeds();
 

  if (distance <= 100) { 
    digitalWrite(led1, HIGH);
    mostrarEnLCDySerial(1, distance);
  } else if (distance <= 200) { 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    mostrarEnLCDySerial(2, distance);
  } else if (distance <= 300) { 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    mostrarEnLCDySerial(3, distance);
  } else if (distance <= 400) { 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
    mostrarEnLCDySerial(4, distance);
  }

  delay(1000);
}

void apagarLeds() {
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
}


void mostrarEnLCDySerial(int ledsEncendidos, int distancia) {
  Serial.print("Distancia: ");
  Serial.print(distancia / 100.0);
  Serial.print(" metros, LEDs encendidos: ");
  Serial.println(ledsEncendidos);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Dist: ");
  lcd.print(distancia / 100.0);
  lcd.print("m");
  lcd.setCursor(0, 1);
  lcd.print("LEDs: ");
  lcd.print(ledsEncendidos);
}