void setup() {
  // put your setup code here, to run once:
  volatile char *ddra,*outa;
  volatile long i,j;
  ddra=0x21;outa=0x22;
  *ddra=0xff;
  while(1){
    *outa=0x07;
    for(j=0;j<400000;j++);
    *outa=0xe0;
    for(j=0;j<400000;j++);
    *outa=0x18;
    for(j=0;j<400000;j++);
  }
}