#include <avr/io.h>
#include <util/delay.h>
#include <Arduino.h>

int main(void)
{
  // I use PB0, PD7, PD6, PD5, PD4, PD3, PD2 for  segment a, b, c, d, e, f, g
  DDRB |= (1 << 0);   // Set LED connected PORT B, Pin 0 as output
  DDRD = 0xff;    // Set PORT D to be 
  for(int i = 0; i <= 13; i++)
  {
    pinMode(i, OUTPUT);
  }

  while (1)
  {   //7segment pull up with VDD connect to pin 3 of the 7segment 
    PORTB = 0b00000000;
    // for PORTD, the order is as follows: b c d e f g X a
    PORTD = 0b00111111; //turns on number 1
    _delay_ms(1000); //delay 1s before displaying the next number
    PORTD = 0b01001000; //turns on number 2
    _delay_ms(1000);
    PORTD = 0b00011000; //turns on number 3
    _delay_ms(1000); 
    PORTD = 0b00110001; //turns on number 4
    _delay_ms(1000);
    PORTD = 0b10010000; //turns on number 5
    _delay_ms(1000); 
    PORTD = 0b10000000; //turns on number 6
    _delay_ms(1000);
    PORTD = 0b00111100; //turns on number 7
    _delay_ms(1000); 
    PORTD = 0b00000000; //turns on number 8
    _delay_ms(1000);
    PORTD = 0b00010000; //turns on number 9
    _delay_ms(1000);
    PORTD = 0b00000100; //turns on number 0
    _delay_ms(1000);
}
}