Edit Arduino Code: Smoothing to average

[adbc22]

Hello,

I am trying to edit the example Arduino code "smoothing" to just take 1 average for the first 10 values and no other averages. Then I want subtract the average from each integer of data from then on and multiple that by -1.

This is the original Arduino Smoothing code:

/*

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 <[e-mail]>
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 readIndex = 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[readIndex];
// read from the sensor:
readings[readIndex] = analogRead(inputPin);
// add the reading to the total:
total = total + readings[readIndex];
// advance to the next position in the array:
readIndex = readIndex + 1;

// if we're at the end of the array...
if (readIndex >= numReadings) {
// ...wrap around to the beginning:
readIndex = 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
}


Here is what I have so far:

/*

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 <[e-mail]>
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);
}

// calculate the average:
average = total / numReadings;
}

I'd really appreciate any help or feedback! Thank you!