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

int trigPin = 4; // assigning trigger pin
int echoPin = 8; //assigning echo pin
long duration, cm, inches;
long sum=0; // initiallly we're assigning as zero
long avg;
int i;

void setup()

{
Serial.begin (9600); //baudrate
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
}

void loop()

{
digitalWrite(trigPin, LOW);
delayMicroseconds(5);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
pinMode(echoPin, INPUT);
duration = pulseIn(echoPin, HIGH);
cm = (duration/2) / 29.1;
inches = (duration/2) / 74;
for (i=0; i<5; i++)
{
sum=sum+inches;
avg = sum/5;
}
Serial.print(avg);
Serial.print("Avg, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
Serial.print(inches);
Serial.print("in");
Serial.println();
delay(250);
}