pendekatan multitasking arduino dengan millis

unsigned long millis_led1=0;
unsigned long millis_led2=0;

void setup() {
pinMode(13,OUTPUT);
pinMode(12,OUTPUT);
pinMode(11,OUTPUT);
pinMode(3,INPUT_PULLUP);
}
void loop() {
if(digitalRead(3)){
  digitalWrite(11,LOW);
}else{
  digitalWrite(11,HIGH);
}

 if(millis()-millis_led1>300){
 digitalWrite(13, !digitalRead(13));
 millis_led1=millis();
 }

if(millis()-millis_led2>1000){
 digitalWrite(12, !digitalRead(12));
 millis_led2=millis();
 }

}