Project 2 - Measuring the distance of an object using ultrasonic sensor and also smoothen the sensor data using moving average filter
#define IN_PIN A0
#define WINDOW_SIZE 5
int INDEX = 0;
int VALUE=0;
int READINGS[WINDOW_SIZE];
int trigPin = 11; // Trigger
int echoPin = 10; // Echo
long duration, cm, inches;
long SUM=0;
long AVERAGED;
int i;
void setup()
{
//Serial Port begin
Serial.begin (9600);
//Define inputs and outputs
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
}
void loop()
{
// The sensor is triggered by a HIGH pulse of 10 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
READINGS[INDEX] = VALUE;
INDEX = (INDEX+1) % WINDOW_SIZE; // Increment the index, and wrap to 0 if it exceeds the window size
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Read the signal from the sensor: 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(echoPin, INPUT);
duration = pulseIn(echoPin, HIGH);
// Convert the time into a distance
cm = (duration*0.034/2) ; // Divide by 29.1 or multiply by 0.0343
inches = (duration/2) / 74;
//Serial.print(inches);
//Serial.print(cm);// Divide by 74 or multiply by 0.0135
for (i=0; i<5; i++)
{
SUM=SUM+inches;
AVERAGED = SUM/5;
// Divide the sum of the window by the window size for the result
}
Serial.print("AVERAGED=");
Serial.print(AVERAGED);
Serial.print(" " );
Serial.print(cm);
SUM=0;
Serial.print("cm,");
//Serial.println();
Serial.print(inches);
Serial.print("in");
Serial.println();
delay(250);
}
