#define PIN_TRIG 3
#define PIN_ECHO 2
#define led 13
bool hoff = true;

void setup() {
  Serial.begin(115200);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
}

void loop() {
  // Inicia uma nova medição:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Leia o resultado:
  int duration = pulseIn(PIN_ECHO, HIGH);
  Serial.print("Distância em CM: ");
  int cm = duration / 58;
  Serial.println(cm);

  if(hoff == true && cm < 15){
    digitalWrite(led, HIGH);
    delay(500);
    digitalWrite(led, LOW);
    Serial.println("Libera álcool, delay 5 seg.");
	  delay(5000);
    hoff = false;
  }else if(cm >=15){
    digitalWrite(led, LOW);
    hoff = true;
  }else{
  	digitalWrite(led, LOW);
  }

  delay(100);
}