byte pin[] = {13, 12, 11, 10, 9, 8}; int i;
unsigned long current;
unsigned long prev1 = 2000;
unsigned long prev2 = 2000;
unsigned long prev3 = 2000;
unsigned long prev4 = 2000;
unsigned long prev5 = 2000;
unsigned long prev6 = 2000;
unsigned long prev7 = 500;
const long event1 = 2000;
const long event2 = 2000;
const long event3 = 2000;
const long event4 = 2000;
const long event5 = 2000;
const long event6 = 2000;


long dt = 2000;
void setup() {


  for (i = 0; i <= 5; i++) {
    pinMode(pin[i], OUTPUT);
  }
  Serial.begin(115200);
}
void op1() {
  if (current - prev1 >= event1) {
    digitalWrite(pin[0], HIGH);
    prev1 = current;
  }
  if (current - prev2 >= event2) {
    digitalWrite(pin[5], HIGH);
    prev2 = current;
  }
  delay(dt);
  digitalWrite(pin[0], LOW);
  digitalWrite(pin[5], LOW);
}
void op2() {
  if (current - prev3 >= event3) {
    digitalWrite(pin[1], HIGH);
    prev3 = current;
  }
  if (current - prev4 >= event4) {
    digitalWrite(pin[4], HIGH);
    prev4 = current;
  }
  delay(dt);
  digitalWrite(pin[1], LOW);
  digitalWrite(pin[4], LOW);
}
void op3() {

  if (current - prev5 >= event5) {
    digitalWrite(pin[2], HIGH);
    prev5 = current;
  }
  if (current - prev6 >= event6) {
    digitalWrite(pin[3], HIGH);
    prev6 = current;
  }
  delay(dt);
  digitalWrite(pin[2], LOW);
  digitalWrite(pin[3], LOW);
}

void loop() {
  current = millis();
  op1();
  op2();
  op3();

}