#define vermelho 6
#define amarelo 5
#define verde 4
#define trig 7
#define echo 8
#define som A3

void setup() {
  pinMode(vermelho, OUTPUT);
  pinMode(amarelo, OUTPUT);
  pinMode(verde, OUTPUT);
  Serial.begin(115200);
  pinMode(trig, INPUT);
  pinMode(echo, INPUT);
  pinMode(som, OUTPUT);
}

void loop() {
  noTone(som);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  int dist = pulseIn(echo,HIGH);
  if(dist/58 > 200){
    digitalWrite(verde, HIGH);
    digitalWrite(vermelho, LOW);
    digitalWrite(amarelo, LOW);
  }else if(dist/58 > 100){
    digitalWrite(amarelo, HIGH);
    digitalWrite(verde, LOW);
    digitalWrite(vermelho, LOW);
  }else{
    if(dist != 0){
      digitalWrite(vermelho, HIGH);
      digitalWrite(verde, LOW);
      digitalWrite(amarelo, LOW);
      tone(som,300,150);
    }
  }
  Serial.println(dist/58);
  delay(500);
}