int trig=12;
int echo=13;
float d;

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(trig, OUTPUT);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(19, OUTPUT);
  pinMode(21, OUTPUT);
  pinMode(22,OUTPUT);
  pinMode(23, OUTPUT);
}
int Ultrasonic()
{
  digitalWrite(trig, LOW);
  delay(20);
  digitalWrite(trig, HIGH);
  delay(100);
  digitalWrite(trig, LOW);
  d =pulseIn(echo, HIGH);
  return(d*0.034/2+1);
  delay(1000);
}

void loop() {
  int distance = Ultrasonic();
  Serial.println(String(Ultrasonic()));

  if(Ultrasonic()<100)
  {
  digitalWrite(21, HIGH);
  digitalWrite(22, LOW);
  digitalWrite(23,LOW);
  }
  else if(Ultrasonic()>100 && Ultrasonic()<200)
  {
    digitalWrite(21, LOW);
    digitalWrite(22, HIGH);
    digitalWrite(23, LOW);
  }
  else if(Ultrasonic()>200  && Ultrasonic()<300)
  {
  digitalWrite(21, LOW);
  digitalWrite(22, LOW);
  digitalWrite(23, HIGH);
  }
  else
  {
  digitalWrite(21,LOW);
  digitalWrite(22, LOW);
  digitalWrite(23, LOW);
  }
}