// set pin numbers:
const int ledPin1 =  13;
const int ledPin2 =  12;
const int ledPin3 =  11;

// Variables will change:
int ledState1 = LOW;  
int ledState2 = LOW; 
int ledState3 = LOW; 
          
long previousMillis1 = 0;        // will store last time LED was updated
long previousMillis2 = 0;
long previousMillis3 = 0;

// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long interval1 = 500;           // interval at which to blink (milliseconds)
long interval2 = 1000; 
long interval3 = 1500; 
void setup() {
	// set the digital pin as output:
	pinMode(ledPin1, OUTPUT);   
  pinMode(ledPin2, OUTPUT);   
  pinMode(ledPin3, OUTPUT);   
}

void loop()
{
	ledblink1();
  ledblink2();
  ledblink3();
}

void ledblink1(){
  unsigned long currentMillis = millis();
	
	if(currentMillis - previousMillis1 > interval1) {
    	// save the last time you blinked the LED 
    	previousMillis1 = currentMillis;   

    	// if the LED is off turn it on and vice-versa:
    	if (ledState1 == LOW)
    	  ledState1 = HIGH;
    	else
    	  ledState1 = LOW;

    	// set the LED with the ledState of the variable:
    digitalWrite(ledPin1, ledState1);
  }
	
}
void ledblink2(){
  unsigned long currentMillis = millis();
	
	if(currentMillis - previousMillis2 > interval2) {
    	// save the last time you blinked the LED 
    	previousMillis2 = currentMillis;   

    	// if the LED is off turn it on and vice-versa:
    	if (ledState2 == LOW)
    	  ledState2 = HIGH;
    	else
    	  ledState2 = LOW;

    	// set the LED with the ledState of the variable:
    digitalWrite(ledPin2, ledState2);
  }
	
}
void ledblink3(){
  unsigned long currentMillis = millis();
	
	if(currentMillis - previousMillis3 > interval3) {
    	// save the last time you blinked the LED 
    	previousMillis3 = currentMillis;   

    	// if the LED is off turn it on and vice-versa:
    	if (ledState3 == LOW)
    	  ledState3 = HIGH;
    	else
    	  ledState3 = LOW;

    	// set the LED with the ledState of the variable:
    digitalWrite(ledPin3, ledState3);
  }
	
}