long cm, duration;
const int echoPin = 7;
const int trigPin = 6;
#define LED1 14
void setup() {
pinMode(LED1, OUTPUT);
pinMode(2,OUTPUT);
pinMode(4, INPUT);
Serial.begin(9600);
}

void loop() {
  digitalWrite(2, LOW);
  delayMicroseconds(2);
  digitalWrite(2, HIGH);
  delayMicroseconds(5);
  digitalWrite(2, LOW);
  duration = pulseIn(4, HIGH);


  cm = duration*0.034/2;

  if (cm < 55)
  {
    delay(1000);
    digitalWrite(LED1,HIGH);
    delay(1000);
  
  }
  else
  {
    delay(1000);
    digitalWrite(LED1,LOW);
  }
}