//connect port A to 7 segment display and print 1
#include <stdint.h>

#define DDRA  (*(volatile uint8_t*)0x21)
#define PORTA (*(volatile uint8_t*)0x22)

void setup() {
    DDRA = 0x7F;      
    PORTA = 0x06;     
}

void loop() {
    
}