int tiger=3;
int echo=2;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(tiger, OUTPUT);
pinMode(echo, INPUT);
pinMode(8, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(tiger, HIGH);
delayMicroseconds(10);
digitalWrite(tiger, LOW);
int valor=pulseIn(echo,HIGH)/58;
Serial.println(valor);
delay(100);
if(valor==120){
  digitalWrite(8,HIGH);
}else{
  digitalWrite(8, LOW);
}
}