#define DISPLAYON 0x0c
#define DISPLAYOFF 0x08
#define INPUTMODE 0x06
#define DISPLAYCLR 0x01
#define RETURNHOME 0x02
#define LCD_PORT P0
sbit LCD_RS = P2^5;
sbit LCD_RW = P2^6;
sbit LCD_EN = P2^7;

void write_lcd_command(unsigned char);
void write_lcd_data(unsigned char);
void write_lcd_char(unsigned char x,bit y,unsigned char DATA);

void lcd_init();
void delay20MS();
bit read_busy();
void gotoxy(unsigned char x,bit y);
/***************************************************************/
void lcd_init()
{
	delay20MS();
	delay20MS();  
	write_lcd_command (DISPLAYCLR);//清屏
	while(read_busy());//讀忙標志
	write_lcd_command (0x38);//8位數據發送模式
	while(read_busy());//讀忙標志
	write_lcd_command (DISPLAYON);//0x0C
	while(read_busy());//讀忙標志
	write_lcd_command (INPUTMODE);//input mode
	while(read_busy());//讀忙標志
	write_lcd_command (0x80);//設置LCD開始顯示地址
	while(read_busy());//讀忙標志
	write_lcd_command (DISPLAYCLR);//清屏
}

void delay20MS()//延時時間有待調整
{
	unsigned char i,j;
	for(i = 0; i < 255; i++)
	{
		for(j = 0; j < 100; j++);
	}
}

void write_lcd_command(unsigned char command)
{
	LCD_PORT = command;
	LCD_RS = 0;
	LCD_RW = 0;
	LCD_EN = 1;
	LCD_EN = 0;
}

void write_lcd_data(unsigned char dat)
{
	LCD_PORT = dat;
	LCD_RS = 1;
	LCD_RW = 0;
	LCD_EN = 1;
	LCD_EN = 0;
}

void write_lcd_char(unsigned char x,bit y,unsigned char DAT)
{
	gotoxy( x, y);
	while(read_busy());//讀忙標志
	write_lcd_data(DAT);	
}


bit read_busy()
{
	unsigned char readdata;
	LCD_PORT = 0xff;
	LCD_RS = 0;
	LCD_RW = 1;
	LCD_EN = 1;
	readdata = LCD_PORT;
	LCD_EN = 0;
	if (readdata >> 7)
		return (1);
	else
		return (0);
}

void gotoxy(unsigned char x,bit y)
{
	while(read_busy());//讀忙標志
	if(y)
		write_lcd_command(0xc0 + x);//2 line
	else
		write_lcd_command(0x80 + x);//1 line
}