const int trigPin = 7;
const int echoPin = 6;
const int led =4;
float duration, distance;



void setup() {
  // put your setup code here, to run once:
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led, OUTPUT);
  Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(trigPin, LOW);
digitalWrite(echoPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration * 0.0343)/2;
if(distance >400 || distance < 2)
{
  Serial.print("out of range");
  Serial.print("Time: ");
  Serial.print(duration,2);
  Serial.print(" microseconds\n");
  digitalWrite(led, LOW);
}
else
{
  Serial.print("Distance: ");
  Serial.print(distance,2);
  Serial.print(" cm Time: ");
  Serial.print(duration,2);
  Serial.print(" microseconds\n");
  digitalWrite(led, HIGH);
}
delay(2000);
}