const int trigPin = 2;
const int echoPin =1;

float duration, distance;

void setup()
{
  pinMode(trigPin , OUTPUT);
  pinMode(echoPin , INPUT);
  pinMode(3, INPUT);
}
void loop()
{
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  
  distance = (duration*.0343)/2;
  
  delay(100);
  
  if(distance >= 150){
    digitalWrite(3, HIGH);
  }else{
    digitalWrite(3, LOW);
  }
}