/*****************************************************************************
* HC-SR04 Ultrasonic Sensor
* Code to turn a LED on when an object is within 50cm range
* Author: Kelen C. Teixeira Vivaldini
******************************************************************************/
#include <LiquidCrystal_I2C.h>

#define echo_PIN 2
#define trigger_PIN 3

// Configuração do display LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(trigger_PIN, OUTPUT);
  pinMode(echo_PIN, INPUT);
  lcd.init();
  lcd.backlight();
  // Mensagem de boas-vindas no LCD
  lcd.setCursor(1, 0);
  lcd.print("Class Embedded!");
  delay(2000);
  lcd.clear();
}

float readDistance() {
  digitalWrite(trigger_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(trigger_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigger_PIN, LOW);
  int duration = pulseIn(echo_PIN, HIGH);
  return duration * 0.03420 / 2; //Constante obtida com calibração
}

void loop() {
  float distance = readDistance();

  bool isNearby = distance < 50;
  digitalWrite(LED_BUILTIN, isNearby);
  //Serial
  Serial.print("Distance: ");
  Serial.println(readDistance());
  //I2C
  lcd.setCursor(0, 0);
  lcd.print("Distance ");
  lcd.setCursor(0, 1);
  lcd.print(distance); // Convertendo a variável para string
  lcd.print(" cm"); // Adicionando a unidade de medida
  delay(100);
}