// defining the pins
const int trigPin = 7;
const int echoPin = 6;
// defining variables
float duration;
float distance;
void setup() {
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input 
pinMode(2, OUTPUT);
pinMode(4, OUTPUT);
Serial.begin(9600); // Starts the serial communication
}
void loop() {
// Clears the trigPin
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
// Sets the trigPin on HIGH state for 10 micro seconds
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
    duration = pulseIn(echoPin, HIGH);  //Max = 38ms
// Calculating the distance 
   distance= duration*0.034/2;

if(distance>200){
digitalWrite(4, HIGH);
delay(150);
digitalWrite(4, LOW);}
if(distance<200){
digitalWrite(2, HIGH);
delay(150);
digitalWrite(2, LOW);}
// Send results to Serial Monitor
 
  Serial.print("Distance = ");
  if (distance >= 400 || distance <= 2) {
     Serial.println("Out of range");
  }
  
  else {
    Serial.print(distance);
    Serial.println(" cm");
    delay(500);
  }
  delay(500);
}