void setup() 
{
    Serial.begin(9600);
    pinMode(13, OUTPUT);
    pinMode(12, OUTPUT);
    pinMode(11, OUTPUT);
}

void loop() 
{
    float srednee = RunningAverage();
    Serial.println(srednee);
    if (srednee >= 900)
    {
        digitalWrite(13, LOW);
        digitalWrite(12, LOW);
        digitalWrite(11, LOW);
    }
    else if (srednee < 900 && srednee >= 600)
    {
        digitalWrite(13, HIGH);
        digitalWrite(12, LOW);
        digitalWrite(11, LOW);
    }
    else if (srednee < 600 && srednee >= 300)
    {
        digitalWrite(13, LOW);
        digitalWrite(12, HIGH);
        digitalWrite(11, LOW);
    }
    else if (srednee < 300)
    {
        digitalWrite(13, LOW);
        digitalWrite(12, LOW);
        digitalWrite(11, HIGH);

    }
}




float RunningAverage()
{  
    static float filtredValue = 0.0;
    float newValue = 0.0, koeff;
    newValue = analogRead(A0);
    
    if (abs(newValue-filtredValue) > 10)
    {
        koeff = 0.9;
    }
    else
    {
        koeff = 0.01;
    }
    
    filtredValue += (newValue - filtredValue) * koeff;
    return filtredValue;
}