void setup() {
  // put your setup code here, to run once:
  volatile char *direction = nullptr;
  direction = 0x2d;
  *direction = 0xff;
}

void loop() {
  // put your main code here, to run repeatedly:
  volatile char *output = nullptr;
  output = 0x2e;
  while(1){
    // YELLOW LED
    *output = 0x01; // IN pin is high. 
                    // Therefore, the "COM pin"(common pin -- 5V) 
                    // iS connected to "NO pin"
    delay(1000);
    // BLUE LED
    *output = 0x00;
    delay(1000);
  }
}