Project 2 - Measuring the distance of an object using ultrasonic sensor and also smoothen the sensor data using moving average filter

#include <LiquidCrystal.h>

#define IN_PIN A0
#define WINDOW_SIZE 5

int INDEX = 0;
float VALUE = 0;
int SUM = 0;
int READINGS[WINDOW_SIZE];
int AVERAGED = 0;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const int pingPin = 9;

void setup() {
// initialize serial communication:
Serial.begin(9600);
lcd.begin(16,2);

Serial.begin(9600);
}

void loop() {
// establish variables for duration of the ping, and the distance result
// in inches and centimeters:
long duration, inches, cm;

// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);

// The same pin is used to read the signal from the PING))): a HIGH pulse
// whose duration is the time (in microseconds) from the sending of the ping
// to the reception of its echo off of an object.
pinMode(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH);
VALUE=duration*(0.034/2);
SUM = SUM - READINGS[INDEX]; // Remove the oldest entry from the sum
// VALUE = analogRead(IN_PIN); // Read the next sensor value
READINGS[INDEX] = VALUE; // Add the newest reading to the window
SUM = SUM + VALUE; // Add the newest reading to the sum
INDEX = (INDEX+1) % WINDOW_SIZE; // Increment the index, and wrap to 0 if it exceeds the window size

AVERAGED = SUM / WINDOW_SIZE; // Divide the sum of the window by the window size for the result

Serial.print(VALUE);
Serial.print(",");
Serial.println(AVERAGED);

delay(25);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
lcd.setCursor(0,0);
lcd.print(inches);
lcd.print("in, ");
//lcd.setCursor(0,1);
lcd.print(cm);
lcd.print("cm");
//Serial.print(inches);
// Serial.print("in, ");
//Serial.print(cm);
// Serial.print("cm");
//Serial.println();

delay(100);
}

long microsecondsToInches(long microseconds) {
// According to Parallax's datasheet for the PING))), there are 73.746
// microseconds per inch (i.e. sound travels at 1130 feet per second).
// This gives the distance travelled by the ping, outbound and return,
// so we divide by 2 to get the distance of the obstacle.
// See: https://www.parallax.com/package/ping-ultrasonic-distance-sensor-downloads/
return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds) {
// The speed of sound is 340 m/s or 29 microseconds per centimeter.
// The ping travels out and back, so to find the distance of the object we
// take half of the distance travelled.
return microseconds / 29 / 2;
}