/*
	LCD1602液晶屏四線驅動模塊
	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
	4、程序在原來基礎上只使用了PB口的高四位，即PB4—PB7，PB0—PB3可以做它用

	SunnyTrip
	www.iccavr.com
*/

#include <iom16v.h>

#define RS_CLR	PORTD &= ~(1 << PD3)
#define RS_SET	PORTD |= (1 << PD3)

#define RW_CLR	PORTD &= ~(1 << PD4)
#define RW_SET	PORTD |= (1 << PD4)

#define EN_CLR	PORTD &= ~(1 << PD6)
#define EN_SET	PORTD |= (1 << PD6)

/*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*/
void LCD_write_com(unsigned char com) {
	
	RS_CLR;
	RW_CLR;
	EN_SET;
	PORTB&=0x0f;
	PORTB|= com&0xf0;
	com = com<<4;
	EN_CLR;
	delay_us(1);
	EN_SET;
	PORTB&=0x0f;
	PORTB|= com&0xf0;
	EN_CLR;
	delay_us(1);
}

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

	RS_SET;
	RW_CLR;
	EN_SET;
	PORTB&=0x0f;
	PORTB|= data&0xf0;
	data = data<<4;
	EN_CLR;
	delay_us(1);
	EN_SET;
	PORTB&=0x0f;
	PORTB|= data&0xf0;
	EN_CLR;
}

/*顯示屏清空顯示*/
void LCD_clear(void) {

	LCD_write_com(0x01);
	delay_ms(5);
}

/*顯示屏字符串寫入函數*/
void LCD_write_str(unsigned char x,unsigned char y,unsigned char *s) {
	
    if (y == 0) {
    	LCD_write_com(0x80 + x);
    	}
    else {
    	LCD_write_com(0xC0 + x);
    	}
    
    while (*s) {
    	LCD_write_data( *s);
    	s ++;
    	}
}

/*顯示屏單字符寫入函數*/
void LCD_write_char(unsigned char x,unsigned char y,unsigned char data) {
	
    if (y == 0) {
    	LCD_write_com(0x80 + x);
    	}
    else {
    	LCD_write_com(0xC0 + x);
    	}
    
    LCD_write_data( data);  
}

/*顯示屏初始化函數*/
void LCD_init(void) {
	
	DDRB = 0xFF;						/*I/O口方向設置*/
	DDRD |= (1 << PD3) | (1 << PD4) | (1 << PD6);
	LCD_write_com(0x28);				/*顯示模式設置*/
	delay_ms(15);
	LCD_write_com(0x28);
	delay_ms(5);
	LCD_write_com(0x28);
	delay_ms(5);
	LCD_write_com(0x28);
	
	LCD_write_com(0x08);				/*顯示關閉*/
	LCD_write_com(0x01);				/*顯示清屏*/
	LCD_write_com(0x06);				/*顯示光標移動設置*/
	delay_ms(5);
	LCD_write_com(0x0C);				/*顯示開及光標設置*/
}