#define trigger 2
#define echo 4
#define buzzer 13
#define led1 19
#define led2 33
int distancia;
int duracion;
int canal=0, frec=2000, resolucion=8;

void setup() {
  Serial.begin(115200);
  pinMode(trigger, OUTPUT);
  pinMode(echo, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);

}

void loop() {
  digitalWrite(trigger, LOW);
   delayMicroseconds(2);
   digitalWrite(trigger, HIGH);
   delayMicroseconds(2);
   digitalWrite(trigger, LOW);
   duracion=pulseIn(echo,HIGH);
   duracion=duracion/2;
   distancia=(duracion/2)*0.0343;
   if(distancia<100)
   {tone(buzzer, 1000);
    digitalWrite(13, HIGH);
    digitalWrite(19, HIGH);
    digitalWrite(33, LOW);
    delay(1000);
    digitalWrite(13, HIGH);
    digitalWrite(19, LOW);
    digitalWrite(33, HIGH);
    delay(1000);
    digitalWrite(13, HIGH);
    digitalWrite(19, HIGH);
    digitalWrite(33, LOW);
    delay(1000);
    digitalWrite(13, HIGH);
    digitalWrite(19, LOW);
    digitalWrite(33, HIGH);
    delay(1000);
    digitalWrite(13, HIGH);
    digitalWrite(19, HIGH);
    digitalWrite(33, HIGH);
    delay(20000);
    
   delay(10000);
   }
   else
   {
    noTone(buzzer);
        }
}