int trig=12;
int echo=13;
float d;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(17,OUTPUT); 
  pinMode(4,OUTPUT);
  pinMode(16,OUTPUT);
}
int ultrasonic(){
  digitalWrite(trig, LOW);
  delay(10);
  digitalWrite(trig, HIGH);
  delay(1000);
  digitalWrite(trig, LOW);
  d=pulseIn(echo,HIGH);
  return((d*0.034/2)+1); 
  delay(500);
}

void loop() {
  int distance=ultrasonic();
  Serial.println(String(ultrasonic()));
  if(ultrasonic()<100){
    digitalWrite(4,HIGH);
    digitalWrite(17,LOW); 
    digitalWrite(16,LOW);
  }
  else if(ultrasonic()>100 && ultrasonic()<200){
    digitalWrite(17,HIGH);
    digitalWrite(4,LOW);
    digitalWrite(16,LOW);
  }
  else if(ultrasonic()>200 && ultrasonic()<350){
     digitalWrite(16,HIGH);
    digitalWrite(17,LOW);
    digitalWrite(4,LOW);
  }
  else
  {
   digitalWrite(17,LOW);
    digitalWrite(16,LOW);
    digitalWrite(4,LOW); 
  }
}