/*--------------- by JediRick -----------------
  boolean        (8 bit)   -  [true/false]
  byte           (8 bit)   -  [0-255] unsigned number
  char           (8 bit)   -  [-128 to 127] signed number
  unsigned char  (8 bit)   -  [-128 to 127] signed number
  word           (16 bit)  -  [0-65535] unsigned number
  unsigned int   (16 bit)  -  [0-65535] unsigned number
  int            (16 bit)  -  [-32768 to 32767] signed number
  unsigned long  (32 bit)  -  [0-4,294,967,295] unsigned number usually for millis
  long           (32 bit)  -  [-2,147,483,648 to 2,147,483,647] signed number
  float          (32 bit)  -  [-3.4028235E38 to 3.4028235E38] signed number
  uint8_t        (8 bit)   -  [0-255] unsigned number
  int8_t         (8 bit)   -  [-127 - 127] signed number
  uint16_t       (16 bit)  -  [0-65,535] unsigned number
  int16_t        (16 bit)  -  [-32,768 - 32,767] signed number
  uint32_t       (32 bit)  -  [0-4,294,967,295] unsigned number
  int32_t        (32 bit)  -  [-2,147,483,648 - 2,147,483,647] signed number
  uint64_t       (64 bit)  -  [0-18,446,744,073,709,551,615] unsigned number
  int64_t        (64 bit)  -  [−9,223,372,036,854,775,808 - 9,223,372,036,854,775,807] signed number
  --------------------------------------------*/

#define PINCOUNT 4
#define FADEPINQTY 2
#define BLINKPINQTY 2

uint8_t LEDPINS[PINCOUNT] = {13, 12, 11, 10};
uint16_t INTERVALS[PINCOUNT] = {500, 250, 5, 1};
unsigned long OLDMILLIS[PINCOUNT] = {0, 0, 0, 0};
unsigned long currentMillis = 0;
bool LEDSTATE[BLINKPINQTY] = {LOW, LOW};
uint8_t BRIGHTNESS[FADEPINQTY] = {0, 0};
uint8_t FADEQTY[FADEPINQTY] = {1, 1};

void setup() {
  for (uint8_t i = 0; i < PINCOUNT; i++) {
    pinMode(LEDPINS[i], OUTPUT);
  }
}

void loop() {
  currentMillis = millis();
  blinkLeds();
  fadeLeds();
}

void blinkLeds() {
  for (uint8_t i = 0; i < BLINKPINQTY; i++) {
    if (currentMillis - OLDMILLIS[i] >= INTERVALS[i]) {
      OLDMILLIS[i] = currentMillis;
      if (LEDSTATE[i] == LOW) {
        LEDSTATE[i] = HIGH;
      } else {
        LEDSTATE[i] = LOW;
      }
      digitalWrite(LEDPINS[i], LEDSTATE[i]);
    }
  }
}

void fadeLeds() {
  if (currentMillis - OLDMILLIS[2] >= INTERVALS[2]) {
    OLDMILLIS[2] = currentMillis;
    analogWrite(LEDPINS[2], BRIGHTNESS[0]);
    BRIGHTNESS[0] = BRIGHTNESS[0] + FADEQTY[0];
    if (BRIGHTNESS[0] <= 0 || BRIGHTNESS[0] >= 255) {
      FADEQTY[0] = -FADEQTY[0];
    }
  }
  if (currentMillis - OLDMILLIS[3] >= INTERVALS[3]) {
    OLDMILLIS[3] = currentMillis;
    analogWrite(LEDPINS[3], BRIGHTNESS[1]);
    BRIGHTNESS[1] = BRIGHTNESS[1] + FADEQTY[1];
    if (BRIGHTNESS[1] <= 0 || BRIGHTNESS[1] >= 255) {
      FADEQTY[1] = -FADEQTY[1];
    }
  }
}