#include<stdint.h>
//Connect four LEDs to port B bit 4 to bit 7. Glow MSB 4 LEDs only (bit 7 to bit 4)
#define aport (*(volatile uint8_t*) 0x22)
#define addr  (*(volatile uint8_t*) 0x21)

void setup() {
  // put your setup code here, to run once:
  addr |= (1<<7) | (1<<6) | (1<<5) | (1<<4);
}

void delayy(void){
  volatile uint32_t i;
  for(i=0; i<1000000; i++);
}
void loop() {
  // put your main code here, to run repeatedly:
  aport |= (1<<7) | (1<<6) | (1<<5) | (1<<4);
  delayy();
  aport &= ~((1<<7) | (1<<6) | (1<<5) | (1<<4));
  delayy();
}