/*
	LCD12864液晶屏驅動模塊
	1、可直接嵌入到項目中使用
	2、晶振頻率：1M
	3、如晶振提高低層驅動延時要作相應修改

	AVR_AFA
	www.iccavr.com
*/

#include <iom128v.h>
#include "font.h"

#define RS_CLR	PORTC &= ~(1 << PC2)		/*命令或數據選擇*/
#define RS_SET	PORTC |= (1 << PC2)			/*RS = 1命令，RS = 0數據*/

#define RW_CLR	PORTC &= ~(1 << PC3)		/*讀取或寫入選擇*/
#define RW_SET	PORTC |= (1 << PC3)			/*RW = 1讀，RW = 0寫*/

#define EN_CLR	PORTC &= ~(1 << PC4)		/*讀寫使能信號*/
#define EN_SET	PORTC |= (1 << PC4)			/*下降沿有效*/

#define RST_CLR	PORTC &= ~(1 << PC5)		/*芯片復位腳*/
#define RST_SET	PORTC |= (1 << PC5)			/*高電平復位*/

#define CSA_CLR	PORTC &= ~(1 << PC7)		/*左半屏片選*/
#define CSA_SET	PORTC |= (1 << PC7)			/*高電平選中*/

#define CSB_CLR	PORTC &= ~(1 << PC6)		/*右半屏片選*/
#define CSB_SET	PORTC |= (1 << PC6)			/*高電平選中*/

/*延時函數*/
void delay_us(unsigned int n) {

	if (n == 0) {
		return ;
		}
	while (--n);
}

/*延時函數*/
void delay_ms(unsigned char i) {

	unsigned char a, b;
	for (a = 1; a < i; a++) {
		for (b = 1; b; b++) {
			;
			}
		}
}

/*顯示屏命令寫入函數前半屏*/
void LCD0_write_com(unsigned char com) {
	
	RS_CLR;
	RW_CLR;
	CSA_SET;
	CSB_CLR;
	EN_SET;
	PORTA = com;
	delay_us(1);
	EN_CLR;
}

/*顯示屏命令寫入函數后半屏*/
void LCD1_write_com(unsigned char com) {
	
	RS_CLR;
	RW_CLR;
	CSA_CLR;
	CSB_SET;
	EN_SET;
	PORTA = com;
	delay_us(1);
	EN_CLR;
}

/*顯示屏命令寫入函數*/
void LCD0_write_data(unsigned char data) {

	RS_SET;
	RW_CLR;
	CSA_SET;
	CSB_CLR;
	EN_SET;
	PORTA = data;
	delay_us(1);
	EN_CLR;
}

/*顯示屏命令寫入函數*/
void LCD1_write_data(unsigned char data) {

	RS_SET;
	RW_CLR;
	CSA_CLR;
	CSB_SET;
	EN_SET;
	PORTA = data;
	delay_us(1);
	EN_CLR;
}

/*顯示屏清空顯示*/
void disp_clear(unsigned char x0, unsigned char x1, unsigned char y) {

	unsigned char x;
	
	/*清除高位*/	
	x = x0;
	if (x < 63) {						/*地址在左半屏范圍內*/
		LCD0_write_com(y | 0xB8);
		LCD0_write_com(x | 0x40);
		}
	while (x < x1) {
		LCD0_write_data(0x00);
		x ++;
		if (x > 63) {					/*判斷地址是否越界*/
			break;
			}
		}
	if (x < x1) {						/*地址進入左半屏范圍*/
		LCD1_write_com(y | 0xB8);
		LCD1_write_com(x | 0x40);
		}
	while (x < x1) {
		LCD1_write_data(0x00);
		x ++;
		}

	/*清除低位*/
	x = x0;
	if (x < 63) {						/*地址在左半屏范圍內*/
		LCD0_write_com((y+1) | 0xB8);
		LCD0_write_com(x | 0x40);
		}
	while (x < x1) {
		LCD0_write_data(0x00);
		x ++;
		if (x > 63) {					/*判斷地址是否越界*/
			break;
			}
		}
	if (x < x1) {						/*地址進入左半屏范圍*/
		LCD1_write_com((y+1) | 0xB8);
		LCD1_write_com(x | 0x40);
		}
	while (x < x1) {
		LCD1_write_data(0x00);
		x ++;
		}
}

/*在指定位置顯示一個ASCII 字符*/
void disp_char(unsigned char x, unsigned char y, unsigned char ascii) {

	unsigned char i = 0x00;
	const unsigned char *q;				/*取字庫指針*/
	
	ascii -= 0x20;
	q = &ENGLISH_FONT[ascii * 16];		/*定位指針地址*/

	/*顯示高8位*/	
	i = 0x00;
	if (x < 64) {						/*地址在左半屏范圍內*/
		LCD0_write_com(y | 0xB8);
		LCD0_write_com(x | 0x40);
		while (i < 8) {
			LCD0_write_data(*q);
			q ++;
			x ++;
			i ++;
			if (x > 63) {				/*判斷地址是否越界*/
				break;
				}
			}
		}
	if (i < 8) {						/*地址進入左半屏范圍*/
		LCD1_write_com(y | 0xB8);
		LCD1_write_com(x | 0x40);
		while (i < 8) {
			LCD1_write_data(*q);
			q ++;
			x ++;
			i ++;
			}
		}

	/*顯示低8位*/
	i = 0x00;
	x -= 8;
	if (x < 64) {						/*地址在左半屏范圍內*/
		LCD0_write_com((y+1) | 0xB8);
		LCD0_write_com(x | 0x40);
		while (i < 8) {
			LCD0_write_data(*q);
			q ++;
			x ++;
			i ++;
			if (x > 63) {				/*判斷地址是否越界*/
				break;
				}
			}
		}
	if (i < 8) {						/*地址進入左半屏范圍*/
		LCD1_write_com((y+1) | 0xB8);
		LCD1_write_com(x | 0x40);
		while (i < 8) {
			LCD1_write_data(*q);
			q ++;
			x ++;
			i ++;
			}
		}
	CSA_CLR;
	CSB_CLR;
}

/*在指定位置顯示一個漢字*/
void disp_word(unsigned char x, unsigned char y, unsigned char word) {

	unsigned char i = 0x00;
	const unsigned char *q;				/*取字庫指針*/
	
	q = &CHINESE_FONT[word * 32];		/*定位指針地址*/

	/*顯示高16位*/	
	i = 0x00;
	if (x < 64) {						/*地址在左半屏范圍內*/
		LCD0_write_com(y | 0xB8);
		LCD0_write_com(x | 0x40);
		while (i < 16) {
			LCD0_write_data(*q);
			q ++;
			x ++;
			i ++;
			if (x > 63) {				/*判斷地址是否越界*/
				break;
				}
			}
		}
	if (i < 16) {						/*地址進入左半屏范圍*/
		LCD1_write_com(y | 0xB8);
		LCD1_write_com(x | 0x40);
		while (i < 16) {
			LCD1_write_data(*q);
			q ++;
			x ++;
			i ++;
			}
		}

	/*顯示低16位*/
	i = 0x00;
	x -= 16;
	if (x < 64) {						/*地址在左半屏范圍內*/
		LCD0_write_com((y+1) | 0xB8);
		LCD0_write_com(x | 0x40);
		while (i < 16) {
			LCD0_write_data(*q);
			q ++;
			x ++;
			i ++;
			if (x > 63) {				/*判斷地址是否越界*/
				break;
				}
			}
		}
	if (i < 16) {						/*地址進入左半屏范圍*/
		LCD1_write_com((y+1) | 0xB8);
		LCD1_write_com(x | 0x40);
		while (i < 16) {
			LCD1_write_data(*q);
			q ++;
			x ++;
			i ++;
			}
		}
	CSA_CLR;
	CSB_CLR;
}

/*顯示一串字符*/
void disp_char_str(unsigned char x, unsigned char y, unsigned char *str) {

	while (*str != 0) {
		disp_char(x, y, *str);
		x += 8;
		str ++;
		}
}

/*顯示屏初始化函數*/
void disp_init(void) {
	
	DDRA = 0xFF;						/*I/O口方向設置*/
	DDRC = 0xFF;

	RST_CLR;
	delay_ms(10);
	RST_SET;

	LCD0_write_com(0xC0);				/*顯示起行設置*/
	LCD1_write_com(0xC0);
	
	LCD0_write_com(0x3F);				/*開顯示設置*/
	LCD1_write_com(0x3F);
}