Sensor smoothing function

gistfile1.ino

/* Sensor smoothing
   by Eric Forman [www.ericforman.com]
   Original version 2008, updated May 2012

   Smooths sensor readings by adding only a fraction of new values.
   The more the new value is divided, the smaller the change, thus a smoother result
   As with any smoothing function, the more you smooth, the slower the response time
*/

int   sensorPin = 0;                    // sensor input pin
int   rawVal = 0;                       // sensor raw value
float smoothedVal = 0.0;                // sensor smoothed value
//float smoothedVal2 = 0.0;             // add additional sensor inputs if you want
float smoothStrength = 5;               // amount of smoothing (default 10)

void setup() {
  Serial.begin(9600);
}

void loop() {
    rawVal = analogRead(sensorPin);
    delay(10);                          // tiny delay to give ADC time to recover

    smoothedVal = smooth(rawVal, smoothedVal);

    // use either or both values:
    //Serial.print(rawVal);
    //Serial.print("t");
    Serial.print(int(smoothedVal));     // * int() truncates float decimal places *
    Serial.println();
}

float smooth(int t_rawVal, float t_smoothedVal) {
    return  t_smoothedVal + ((t_rawVal - t_smoothedVal) + 0.5) / smoothStrength;  // +0.5 for rounding
}