void setup() {
 volatile char *dir;
   dir = 0x30;
   *dir = 0xFF; 
   
   dir = 0x107;
   *dir = 0xFF;

}

void loop() {
 
  volatile char *out;
  //volatile long i;

  out = 0x108;
  *out = 0x01;  //try 0x03 or 0b00000011 //try 0x02

  out = 0x31;
  *out = 0x01;

   //for(i=0;i<100000;i++); //try uncommenting it out
    out = 0x108;
   *out = 0x02;  //try 0x03 or 0b00000011 //try 0x01

   out = 0x31;
  *out = 0x01; 

  //for(i=0;i<100000;i++); //try uncommenting it out
}