int trig=12;
int echo=14;
int distance;
void setup() {
Serial.begin(115200);
pinMode(trig, OUTPUT);
pinMode(echo,INPUT);
pinMode(4, OUTPUT);
pinMode(16, OUTPUT);
pinMode(17, OUTPUT);
}

void loop()
{
   digitalWrite(trig,HIGH);
 Serial.println("vanakam da mapla");
  delay(1000); 
  digitalWrite(trig, LOW);
  distance = pulseIn(echo, HIGH);
  Serial.println("Thenila irundhu");
  float c = (distance*0.034/2);
  Serial.println(c);
  if (c>300)
  {
  digitalWrite(4, HIGH);
  digitalWrite(16, LOW);
  digitalWrite(17, LOW);
  }
  else if (c>200)
  {
    digitalWrite(16, HIGH);
    digitalWrite(4, LOW);
    digitalWrite(17, LOW);
  }
  else if (c<100)
  {
    digitalWrite(17, HIGH);
    digitalWrite(4, LOW);
    digitalWrite(16, LOW);
  }
}