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

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int ECHO = 11;
const int TRIG = 12;
int duracao = 0;
long distancia = 0;
int red = 0;
int yel = 0;
int gre = 0;
const int buzzer = 2;



void setup() {

  Serial.begin(9600);
  pinMode(ECHO, INPUT);
  pinMode(TRIG, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(8, OUTPUT); 
  lcd.begin(16, 2);
}

void loop() {
  digitalWrite(TRIG, LOW);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  duracao = pulseIn(ECHO, HIGH);
  distancia = duracao / 58;
  Serial.print("Distancia em cm: ");
  Serial.println(distancia);
  delay(100);

  digitalWrite(TRIG, LOW);
  delayMicroseconds(10);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  duracao = pulseIn(ECHO, HIGH);
  distancia = duracao / 58;

  if (distancia < 5){

    digitalWrite(10, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    tone(buzzer, 1200);
    delay(200);
    noTone(buzzer);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("PARE!!!          ");


  } else if (distancia >= 5 && distancia < 10) {
    digitalWrite(10, LOW);
    digitalWrite(9, HIGH);
    digitalWrite(8, LOW);
    tone(buzzer, 1200 - (distancia - 2) * 100);
    delay(500);
    noTone(buzzer);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("ATENCAO: ");
    lcd.print(distancia);
    lcd.print(" cm        ");


  } else if (distancia > 10) {
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, HIGH);
    delay(1000);
    noTone(buzzer);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("SEGURO: ");
    lcd.print(distancia);
    lcd.print(" cm         ");
  }

}