#define Delay 600000
void setup() {
  // put your setup code here, to run once:
  char *dir;
  dir=0x30;
  *dir=0xFF;
}

void loop() {
  // put your main code here, to run repeatedly:
  volatile char x;
  volatile char *out;
  out=0x31;
  volatile long i;
  volatile long j;
  //x=128;
  //*out=x;
  /*for (x=0;x<8;x++){
    *out=( 3 << x );
    for (i=0;i<200000;i++);
  }
  for (x=7;x>0;x--){
    *out=( 3 << x );
    for(i=0;i<=200000;i++);
  }*/

  for(i=1;i<=255;i=(i<<1)+1)
  {
    *out=i;
    for(j=0;j<=Delay;j++);
    *out=0x00;
    for(j=0;j<=Delay;j++);
  }


  /*for(i=1;i<=255;i=(i<<1)+1)
  {
    *out = i;
    for(j=0;j<Delay;j++);
    *out = 0x00;
    for(j=0;j<Delay;j++);
  }*/


  //x=0;
  //*out=x;
  //for (i=0;i<100000;i++);

    /**out=(1 << x);
    for (i=0;i<=100000;i++);
  }
  /*01010101
  10101010
  00000011
  11000000
  1000 -8
  1001 -9
  1010 -A
  1011 -B
  1100 -C
  1101 -D
  1110 -E
  1111 -F
  00001111 -
  10001101 
  
*/

}