int LEDRED =  6;
int LEDYELLOW =  5;
int LEDBLUE =  3;
int LEDGREEN =  1;


const int trigPin = 13;
const int echoPin = 10;
const int bufferSize = 10;
int buffer[bufferSize];
int index;
// defines variables
long duration;
int distance;
void setup() {

pinMode(LEDBLUE, OUTPUT);
pinMode(LEDRED, OUTPUT);
pinMode(LEDGREEN, OUTPUT);
pinMode(LEDYELLOW, OUTPUT);

pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
Serial.begin(9600); // Starts the serial communication
}
void loop() {
  
   adddistance(distance);

   //RED
if (distance > 0 && distance <= 100) 
{
digitalWrite(LEDRED, HIGH);
digitalWrite(LEDYELLOW, LOW);
digitalWrite(LEDBLUE, LOW);
digitalWrite(LEDGREEN, LOW);
}
//GREEN
else if (distance > 100 && distance <= 200) 
{
digitalWrite(LEDRED, LOW);
digitalWrite(LEDYELLOW, LOW);
digitalWrite(LEDBLUE, LOW);
digitalWrite(LEDGREEN, HIGH);
}
// BLUE
 else if (distance > 200 && distance <= 300) 
{
digitalWrite(LEDRED, LOW);
digitalWrite(LEDYELLOW, LOW);
digitalWrite(LEDBLUE, HIGH);
digitalWrite(LEDGREEN, LOW);
}
//YELLOW
else if (distance > 300 && distance <= 400) 
{
digitalWrite(LEDRED, LOW);
digitalWrite(LEDYELLOW, HIGH);
digitalWrite(LEDBLUE, LOW);
digitalWrite(LEDGREEN, LOW);
}

}
void adddistance(int distance)
{
    // Clears the trigPin
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin on HIGH state for 10 microseconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculating the distance
distance= duration*0.0343/2;
Serial.print(distance);Serial.print("\t");Serial.println(average());
  buffer[index] = distance;
  index++;
  if (index >= bufferSize) index = 0;


}

int average()
{
  long sum = 0;
  for (int i = 0; i < bufferSize; i++)
  {
    sum += buffer[i];
  }
  return (int)(sum / bufferSize);
}