void setup() {
  // put your setup code here, to run once:
 volatile char* k;
  k=(char*)0x30;
  *k=0xFF;

}


void loop() {
  // put your main code here, to run repeatedly:
volatile char *p;

  volatile long i;

  p=(char*)0x31;

  *p=1;
for(i=0;i<60000;i++);
*p=0;
for(i=0;i<60000;i++);


}