#define LEDPIN 11
long avg;
void setup(){
  Serial.begin(19200);
  avg=0;
  for(int i=0;i<50;i++)avg+=analogRead(A0);
  avg+=25;
  avg/=50;
  Serial.print("avg: ");
  Serial.println(avg);
  pinMode(LEDPIN,OUTPUT);
}

#define NSAMPLE 10
void loop(){
  int raw,i;
  long x=0,locavg=0;
  for(i=0;i<NSAMPLE;i++){
    raw=analogRead(A0);
    locavg+=raw;
    x+=abs(raw-avg);
  }
  //locavg+=NSAMPLE/2;
  locavg/=NSAMPLE;
  avg=(avg*19+locavg)/20;
  
  x/=NSAMPLE;
  Serial.println(x);
  analogWrite(LEDPIN,(byte)x);
  delay(50);
  
  
}//end loop