int trig=13;
int echo=12;
int distance;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(17, OUTPUT);
  pinMode(16, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
  digitalWrite(trig, HIGH);
  delay(1000);
  digitalWrite(trig, LOW);
  int reading=(pulseIn(echo,HIGH));
  distance=(reading*0.034/2);
  if(distance<100)
  {
    digitalWrite(17, HIGH);
    digitalWrite(16, LOW);
    digitalWrite(4, LOW);
  }
  else if(distance<200)
  {
    digitalWrite(17, LOW);
    digitalWrite(16, HIGH);
    digitalWrite(4, LOW);
  }  
  else if(distance<300)
  {
    digitalWrite(17, LOW);
    digitalWrite(16, LOW);
    digitalWrite(4, HIGH);
  }
    
    // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}