#define LED_RED 4
#define LED_GREEN 0

bool state_red = HIGH;
bool state_green = HIGH;


void setup() {
  // put your setup code here, to run once:
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);

}

const unsigned long interval_red = 1000;
const unsigned long interval_green = 300;

void loop() {
  // put your main code here, to run repeatedly:
  static unsigned long previousMillis_red = 0;
  static unsigned long previousMillis_green = 0;
  unsigned long currentMillis = millis();

 if (currentMillis - previousMillis_red >= interval_red) {
    digitalWrite(LED_RED, state_red);
    previousMillis_red = currentMillis;
    state_red = !state_red;
  }
 if (currentMillis - previousMillis_green >= interval_green) {
    digitalWrite(LED_GREEN, state_green);
    previousMillis_green = currentMillis;
    state_green = !state_green;
  }
  /*
  digitalWrite(LED_RED, state_red);
  digitalWrite(LED_GREEN, state_green);
  state_red = !state_red;
  state_green = !state_green;
  delay(500);
  */

}