void setup() {
  // put your setup code here, to run once:
  volatile char *dirf;
  volatile char *outf;
  volatile long i, j, x;
  dirf = 0x30;
  outf = 0x31;
  *dirf = 0xFF;
  
  
  /*while(1)
  {
    *outf = 0x01;
    //delay(1000);
    for(i=0; i<1000000; i++);
    *outf = 0x00;
    //delay(100);
    for(i=0; i<100000; i++);
  }*/
  //*outf = 0x00;

  while(1)
  {
    *outf = 0x00;
    delay(10);

    for(i=0; i<=255; i++)
    {
      x = (log(i+1) * 255/log(256));
      *outf = (x>0) ? 0x01 : 0x00;
      delay(100);
    }

    /*for(i=0; i<=255; i++)
    {
      x = (i*255)/100;
      *outf = (*outf & 0xFE) | (x & 0x01);
      delay(50);
    }*/
    /*for(i=0; i<=255; i++)
    {
      if((i & 0x01) == 0x01)
      {
        *outf = 0x01;
      }
      else{
        *outf = 0x00;
      }
      delay(100);
    }*/

    *outf = 0x01;
    delay(100);

    for(i=255; i>=0; i--)
    {
      x = (log(i+1) * 255/log(256));
      *outf = (x>0) ? 0x01 : 0x00;
      delay(10);
    }

    

    /*for(i=255; i>=0; i--)
    {
      x = (i*255)/100;
      *outf = (*outf & 0xFE) | (x & 0x01);
      delay(50);
    }*/
    /*for(i=255; i>=0; i--)
    {
      if((i & 0x01) == 0x01)
      {
        *outf = 0x01;
      }
      else{
        *outf = 0x00;
      }
      delay(100);
    }*/
  }




  

  

}

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

}