/*Write a program to display only even  numbers in binary form, using 4 LEDs, with a 
delay of 1 sec. When it reaches the maximum value, wait 2 seconds and start from the 
minimum.*/

const int pins[] = {1, 5, 9, 13};

void setup() {
  // put your setup code here, to run once:
  Serial1.begin(115200);
  for (int i = 0; i < 4; i++)
    pinMode(pins[i], OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

  int arr[15][4];

    for (int i = 0; i < 15; i++)
    {
        int num = i + 1;
        for (int j = 3; j >= 0; j--)
        {
          int n = num % 2;
          num = num / 2;
          arr[i][j] = n;
        }
    }

    for (int i = 1; i < 15; i = i + 2)
    {
      for (int j = 0; j < 4; j++)
      {
        if (arr[i][j] == 1)
        {
          digitalWrite(pins[j], HIGH);
        }
        else
        {
          digitalWrite(pins[j], LOW);
        }
      }
      delay(2500);
    }
    delay(5000);
}