// https://wokwi.com/projects/398309878002672641
// https://forum.arduino.cc/t/strategy-for-flashing-leds/1260933

// preliminary test for status LED object

const byte leds[] = {2, 3, 4, 5,};
const byte type[] = {0b100, 0b1000, 0b11000, 0b111000,};

const byte nLEDs = sizeof leds / sizeof *leds;

void setup() {
  Serial.begin(115200);
  Serial.println("\nbit flash world!");

  for (int ii = 0; ii < nLEDs; ii++) pinMode(leds[ii], OUTPUT);
}

# define RATE 64

void loop() {
  static unsigned long lastTime;

  unsigned long now = millis();

  if (now - lastTime < RATE) return;
  lastTime = now;

  static byte flashCounter;

  flashCounter++;

  for (int ii = 0; ii < nLEDs; ii++) {
    bool thisLED = (flashCounter & type[ii]) == type[ii];
    digitalWrite(leds[ii], thisLED ? HIGH : LOW);
  }
}

/* WTF
    Serial.print(flashCounter, 2);
    Serial.print(" ");
    Serial.print(type[ii] & flashCounter);
    Serial.print(" ");
    Serial.println(" ");
*/