const int relayPin = 12;
const int ledPin = 10;
const unsigned long Led_Interval = 600;
const unsigned long Relay_Interval = 2000;

byte ledState = LOW;
byte relayState = LOW;

unsigned long currentMillis = 0; 
unsigned long previousLeds_Millis = 0;
unsigned long previousRelay_Millis = 0;

void setup() 
{
  pinMode( relayPin, OUTPUT);
  pinMode( ledPin, OUTPUT);
}

void loop() 
{
  currentMillis = millis();

  updateLedState();
  updateRelayState();
  switchLed();
  //switchRelay();
}

void updateLedState(){
  if(ledState == LOW){
    if (currentMillis - previousLeds_Millis >= Led_Interval) {
      ledState = HIGH;
      previousLeds_Millis =+ Led_Interval;
    }
  }else{
     ledState = LOW;
  }
};

void updateRelayState(){
  if(relayState == LOW){
    if (currentMillis - previousRelay_Millis >= Relay_Interval) {
      relayState = HIGH;
      previousRelay_Millis =+ Relay_Interval;
    }
  }else{
     relayState = LOW;
  }
};

void switchLed(){
  digitalWrite( ledPin, ledState);
}

void switchRelay(){
  digitalWrite( relayPin, relayState);
}