int trig = 5;
int echo = 17;

int led1 = 2;
int led2 = 15;
int led3 = 16;

int buzzer = 14;

long duracao;
float distancia;

void setup() {
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);

  pinMode(buzzer, OUTPUT);

  Serial.begin(115200);
}

void loop() {

  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  duracao = pulseIn(echo, HIGH);
  distancia = duracao * 0.034 / 2;

  Serial.println(distancia);


  if (distancia <= 10) {
    
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);

    tone(buzzer, 2000); // contínuo forte
  }

  else if (distancia <= 20) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, LOW);

    bipRapido();
  }

  else if (distancia <= 30) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);

    bipLento();
  }

  else {
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);

    noTone(buzzer);
  }

  delay(50);
}

void bipLento() {
  tone(buzzer, 1000);
  delay(300);
  noTone(buzzer);
  delay(700);
}

void bipRapido() {
  tone(buzzer, 1000);
  delay(150);
  noTone(buzzer);
  delay(150);
}