#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

#define trig_pin 5
#define echo_pin 4
#define l_verde 6
#define l_vermelho 8
#define buzzer 2
int print_timer;

void setup ()
{
  lcd.init();
  lcd.backlight();
  lcd.print("ULTRASSOM");
  Serial.begin(9600);
  pinMode(trig_pin, OUTPUT);
  pinMode(echo_pin, INPUT);
  pinMode(l_verde, OUTPUT);
  pinMode(l_vermelho, OUTPUT);
  pinMode(buzzer, OUTPUT);
  digitalWrite(trig_pin, LOW);
}

void loop()
{
  if(millis() - print_timer > 500)
  {
    print_timer = millis();
    digitalWrite(trig_pin, HIGH);
    delayMicroseconds(11);
    digitalWrite(trig_pin, LOW);
    int pulse_time = pulseIn(echo_pin, HIGH);
    double distance = 0.01715*pulse_time;
    Serial.print("Distancia: ");
    Serial.print(distance);
    Serial.println( " cm");
    if (distance>100){
      digitalWrite(l_vermelho, HIGH);
      digitalWrite(l_verde, LOW);
    } else{
      digitalWrite(l_vermelho, LOW);
      digitalWrite(l_verde, HIGH);
    }
    lcd.setCursor(0, 1);
    lcd.print("Dist: ");
    lcd.print(distance);
    lcd.print(" cm");
  }
}