cloud_flashes.ino

#define NUM_LEDS 6
#define OFF 0
#define ON 1

int PINS[] = {5, 4, 0, 2, 14, 12};

void setup() {
  Serial.begin(115200);

  for(int i = 0; i < NUM_LEDS; i++) {
    pinMode(PINS[i], OUTPUT); 
    digitalWrite(PINS[i], OFF);
  }
}

void loop() {

  // select a current LED to flash
  int currentLED = PINS[random(0, NUM_LEDS - 1)];
  Serial.println(currentLED);

  // flash 1 - 3 times
  int flashs = random(1, 3);
  for(int f = 0; f <= flashs; f++) {

    int baseTime;
    switch(flashs) {
      case 1: baseTime = 100; break;
      case 2: baseTime = 70; break;
      case 3: baseTime = 50; break;
    }
    
    // flash
    digitalWrite(currentLED, 1);
    delay(random(baseTime - 20, baseTime + 20));
    digitalWrite(currentLED, 0);
    delay(random(baseTime - 20, baseTime + 20));
  }

  // wait a random amount of time
  delay(random(random(398, 425), random(1981, 2624)));
}