/***************************************************************************/
/*    使用中斷方式                                                         */ 
/*    SCK   ----  INT1                                                     */
/*    DATA  ----  PB0                                                      */
/*    M16 內部8MHz，FUSE =0XD9D4 ICCAVR7.13測試通過                        */
/*    EndyLu AVR 2.0                                                       */
/***************************************************************************/

#include<iom16v.h>
#include<macros.h>
#include "scancodes.h"

#define BAUD  9600
#define BARR  (7372800/(16*BAUD)-1)


volatile unsigned char keycode=0;
volatile unsigned char step=0;
volatile char flag=0;

static unsigned char Key_UP=0, Shift = 0;//Key_UP是鍵松開標識，Shift是Shift鍵按下標識
static unsigned char BF = 0; //標識是否有字符被收到

void port_init(void)
{
	DDRD =  0Xe7;
    PORTD = 0XFF;

}

void UART_init( void )
{
	UBRRH = (unsigned char)(BARR>>8);
	UBRRL = (unsigned char)BARR;
	UCSRB = (1<<RXEN)|(1<<TXEN);
	UCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0);       
}

void uart_transmit(unsigned char data)
{
	while(!(UCSRA&(1<<UDRE)));
	
	UDR = data;
}

void uart_trans_str(unsigned char *s)
{
 	while(*s)
	{
	 uart_transmit(*s);
	 s++;
	}
}
#pragma interrupt_handler int1_scr:3
void int1_scr(void)
{
	step++;
	
	if(step==1)
	{
		if((PIND&0X10)==1)
		{
			step = 0;
		}
	}
	else if((step>=2)&&(step<=9))
	{	
		keycode>>=1;
		
		if((PIND&0X10)==0)
		{
			keycode|=0x00;
		}
		else 
		{
			keycode|=0x80;
		}	   
	}
	else if(step == 11)
	{
		flag = 1;
		step = 0;
	}
}

void Decode(unsigned char ScanCode) //注意:如SHIFT+G為12H 34H F0H 34H F0H 12H，也就是說shift的通碼+G的通碼+shift的斷碼+G的斷碼
{
	unsigned char TempCyc;	

	if (!Key_UP)                //當鍵盤松開時
		{
			switch (ScanCode)
				{
					case 0xF0 :	// 當收到0xF0，Key_UP置1表示斷碼開始
						Key_UP = 1;
					break;

					case 0x12 :	// 左 SHIFT
						Shift = 1;
					break;

					case 0x59 :	// 右 SHIFT
						Shift = 1;
					break;

					default:						
						if(!Shift)	//如果SHIFT沒按下
							{
								for (TempCyc = 0;(UnShifted[TempCyc][0]!=ScanCode)&&(TempCyc<59); TempCyc++); //查表顯示
								if (UnShifted[TempCyc][0] == ScanCode) 
								    uart_transmit(UnShifted[TempCyc][1]);
							} 
						else  //按下SHIFT
							{
								for(TempCyc = 0; (Shifted[TempCyc][0]!=ScanCode)&&(TempCyc<59); TempCyc++); //查表顯示
								if (Shifted[TempCyc][0] == ScanCode)
								   uart_transmit(Shifted[TempCyc][1]);
							}

					break;
				}
		}
	else
		{	
			Key_UP = 0;
			switch (ScanCode) //當鍵松開時不處理判碼，如G 34H F0H 34H 那么第二個34H不會被處理
				{
					case 0x12 :	// 左 SHIFT
						Shift = 0;
					break;

					case 0x59 :	// 右 SHIFT
						Shift = 0;
					break;
				}
		}
	BF = 0; //標識字符處理完了
} 


void main(void)
{
    unsigned int i;
	CLI(); //disable all interrupts
 	port_init();
 	UART_init();
	MCUCR = 0x08;
 	GICR  = 0x80;
 	SEI();
	for(i=0;i<60000;i++)//延時
	;
	uart_transmit('\n');		
	uart_trans_str("     Welcome You!");
	uart_transmit('\n');		
	uart_trans_str("    You are the best!");	
	uart_transmit('\n');
	uart_trans_str("   EndyLu AVR 2.0");
	uart_transmit('\n');
	uart_trans_str(" PS2 Keyboard test program 1.0");	
	uart_transmit('\n');
	uart_trans_str("Please input with keyboard:");
	while(1)
	{
	
	 	if(flag ==1)
	 	{ 
		  	//uart_transmit(keycode); //發送未解碼信息，了解原理時可用
		    Decode(keycode);   //鍵盤解碼
	 		 
			keycode = 0;
			
			flag = 0;
	    }
	} 
 }