/*
  AnalogReadSerial
 Reads an analog input on pin 0, prints the result to the serial monitor 
 
 This example code is in the public domain.
 */

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

double delta=0;
int lastV=0;
int v=0;
double epsilon=0.004;
double delsq=0;
double mean=0;

void loop() {
  for (int i=0; i<100; ++i) {
  lastV = v; 
  v = analogRead(A0);
  mean = mean*(-epsilon+1.0)+epsilon*v;
  delta=(delta+double(v-lastV))*epsilon;
  
  
  delsq = (mean-double(v))*(mean-double(v))*epsilon + delsq*(-epsilon+1.0);
  
  
  }
  
  
  Serial.print(v);
  Serial.print("\t");
  Serial.print(mean);
  Serial.print("\t");
  Serial.print(delta);
  Serial.print("\t");
  Serial.println(sqrt(delsq));
}