void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(16, INPUT);
  pinMode(19, OUTPUT);
  pinMode(33, OUTPUT);
}

void loop() {
 digitalWrite(19, HIGH);
 delay(1000);
 digitalWrite(19, LOW);

 int duration = pulseIn(16, HIGH);
 float distance = duration*0.034/2;

 Serial.println(distance);
 delay(1000);
  if(distance>200 && distance<=400){
  digitalWrite(33, HIGH);
  Serial.println(distance);
  
  }
  else {
    digitalWrite(33, LOW);
    Serial.println(distance);
    delay(1000);
    
  }
}