#include <avr/io.h>
#include <avr/interrupt.h>

static char scandata[32] = 
{
  0b10101111,//0
  0b10100000,//1
  0b11000111,//2
  0b11100110,//3
  0b11101000,//4
  0b01101110,//5
  0b01101111,//6
  0b10100010,//7
  0b11101111,//8
  0b11101110,//9
  0b11101011,//A
  0b01101101,//b
  0b00001111,//C
  0b11100101,//d
  0b01001111,//E
  0b01001011,//F
  0b10111111,//0
  0b10110000,//1
  0b11010111,//2
  0b11110110,//3
  0b11111000,//4
  0b01111110,//5
  0b01111111,//6
  0b10110010,//7
  0b11111111,//8
  0b11111110,//9
  0b11111011,//A
  0b01111101,//b
  0b00011111,//C
  0b11110101,//d
  0b01011111,//E
  0b01011011,//F
};

void init_tc0(void)
{
	TCNT0 = 0;
	TIMSK |= (1 << TOIE0);//使能TC0溢出中斷
	TCCR0 |= (1 << CS02);//256分頻
}

static void scan_smg(char num,char *data)
{
	switch(num & 0x03)
	{
		case 0:
		{
			PORTC &= ~(1 << 6);
			PORTB = scandata[data[0]];
			PORTD |= (1 << 5);
			break;
		}
		case 1:
		{
			PORTD &= ~(1 << 5);
			PORTB = scandata[data[1]];
			PORTD |= (1 << 4);
			break;
		}
		case 2:
		{
			PORTD &= ~(1 << 4);
			PORTB = scandata[data[2]];
			PORTC |= (1 << 7);
			break;
		}
		case 3:
		{
			PORTC &= ~(1 << 7);
			PORTB = scandata[data[3]];
			PORTC |= (1 << 6);
			break;
		}
		default:
		{
			break;
		}
	}
}

volatile static char smg_num = 0,smg_dis_buf[4] = {0};
void write_smg(char * data)
{
	char i = 0;
	DDRD &= ~(1 << 6);
	PORTD |= (1 << 6);
	DDRD &= ~(1 << 7);
	PORTD |= (1 << 7);
	DDRD &= ~(1 << 2);
	PORTD |= (1 << 2);
	DDRD &= ~(1 << 3);
	PORTD |= (1 << 3);

	DDRB = 0xff;

	DDRD |= 0x30;
	DDRC |= 0xC0;
	
	init_tc0();
	for(i = 0;i < 4;i ++)
	{
		smg_dis_buf[i] = data[i];
	}
}

void un_init_smg(void)
{
	TCCR0 = 0;
	PORTC &= ~(1 << 6);
	PORTD &= ~(1 << 5);
	PORTD &= ~(1 << 4);
	PORTC &= ~(1 << 7);
}
SIGNAL(SIG_OVERFLOW0)
{
	scan_smg(smg_num ++,smg_dis_buf);
}