/*

    Smoothing

    Reads repeatedly from an analog input, calculating a running average
    and printing it to the computer.  Keeps ten readings in an array and
    continually averages them.

    The circuit:
      * Analog sensor (potentiometer will do) attached to analog input 0

    Created 22 April 2007
    By David A. Mellis  <dam@mellis.org>
    modified 9 Apr 2012
    by Tom Igoe
    http://www.arduino.cc/en/Tutorial/Smoothing

    This example code is in the public domain.


  */


  // Define the number of samples to keep track of.  The higher the number,
  // the more the readings will be smoothed, but the slower the output will
  // respond to the input.  Using a constant rather than a normal variable lets
  // use this value to determine the size of the readings array.
  const int numReadings = 10;

  int readings[numReadings];      // the readings from the analog input
  int index = 0;                  // the index of the current reading
  int total = 0;                  // the running total
  int average = 0;                // the average

  int inputPin = A0;

  void setup()
  {
    // initialize serial communication with computer:
    Serial.begin(9600);
    // initialize all the readings to 0:
    for (int thisReading = 0; thisReading < numReadings; thisReading++)
      readings[thisReading] = 0;
  }

  void loop() {
    // subtract the last reading:
    total= total - readings[index];
    // read from the sensor:
    readings[index] = analogRead(inputPin);
    // add the reading to the total:
    total= total + readings[index];
    // advance to the next position in the array:
    index = index + 1;

    // if we're at the end of the array...
    if (index >= numReadings)
      // ...wrap around to the beginning:
      index = 0;

    // calculate the average:
    average = total / numReadings;
    // send it to the computer as ASCII digits
    Serial.println(average);
    delay(1);        // delay in between reads for stability
  }