液晶1602的驱动程序（8PIN）

工程名称：1602液晶演示
编译器类型及版本：ICCAVR 6.31A
创建人：陆淼坤
创建日期：2005.04.18

芯片类型：ATmega16L
时钟频率：4M外部时钟
硬件接口说明：MCU ~ LCD
PORTD ~ dataport(PD1~DB1...PD7~DB7)
PA1 ~ RS
PA2 ~ RW
PA3 ~ E

修改人：
修改日期：
修改说明：
---------------------------------------------------------------*/
#include iom16v.h
#include macros.h

#define lcd_data_port PORTD
#define lcd_data_ddr DDRD
#define lcd_busy_pin PIND
#define lcd_busy_ddr DDRD
#define lcd_control_port PORTA
#define lcd_control_ddr DDRA

#define lcd_RS 0x01 //PORTA^0
#define lcd_RW 0x02 //PORTA^1
#define lcd_EN 0x04 //PORTA^2
#define busy 0x80 //LCD_DB7

/*----------------------------------函数声明------------------------------------------*/
void lcd_init(void);
void lcd_write_command(unsigned char command,unsigned char wait_en);
void lcd_write_data(unsigned char char_data);
void wait_enable(void);
void display_a_char(unsigned char position,unsigned char char_data);
void display_a_string(unsigned char col,unsigned char *ptr);
void delay_1ms(void);
void delay_nms(unsigned int n);

//显示的两行字符
unsigned char str1[]= neutronlmk ;
unsigned char str2[]= ;

/*------------------------------------主函数-------------------------------------------*/
//在LCD上显示neutronlmk和两行字符
void main(void)
{
lcd_data_port=0xff;
lcd_data_ddr=0xff;
lcd_control_port=0x07;
lcd_control_ddr=0x07;
lcd_init();
display_a_string(0,str1);
display_a_string(1,str2);
while(1);
}

/*------------------------------------液晶驱动函数-------------------------------------*/
//液晶初始化
void lcd_init(void)
{
delay_nms(15);
lcd_write_command(0x38,0);//显示模式设置三次(此时不管lcd空闲与否)
delay_nms(5);
lcd_write_command(0x38,0);
delay_nms(5);
lcd_write_command(0x38,0);
delay_nms(5);

lcd_write_command(0x38,1);//显示模式设置(从此之后均需lcd空闲)
lcd_write_command(0x08,1);//显示关闭
lcd_write_command(0x01,1);//显示清屏
lcd_write_command(0x06,1);//显示光标移动设置
lcd_write_command(0x0c,1);//显示开及光标设置
}

//写指令函数: E=高脉冲 RS=0 RW=0
void lcd_write_command(unsigned char command,unsigned char wait_en)//command为指令，wait_en指定是否要检测LCD忙信号
{
if(wait_en)wait_enable();//若wait_en为1，则要检测LCD忙信号，等待其空闲
lcd_control_port&=~lcd_RS;//RS=0
lcd_control_port&=~lcd_RW;//RW=0
lcd_control_port&=~lcd_EN;//E=0,下面给LCD一个高脉冲
NOP();
lcd_control_port|=lcd_EN;//E=1
lcd_data_port=command;
lcd_control_port&=~lcd_EN;//重设E=0
}

//写数据函数: E =高脉冲 RS=1 RW=0
void lcd_write_data(unsigned char char_data)
{
wait_enable();//等待LCD空闲
lcd_control_port|=lcd_RS;//RS=1
lcd_control_port&=~lcd_RW;//RW=0
lcd_control_port&=~lcd_EN;//E=0,下面给LCD一个高脉冲
NOP();
lcd_control_port|=lcd_EN;//E=1
lcd_data_port=char_data;
lcd_control_port&=~lcd_EN;//重设E=0
}

//正常读写操作之前必须检测LCD控制器状态:E=1 RS=0 RW=1;DB7: 0 LCD控制器空闲，1 LCD控制器忙。
//检测忙信号,等待LCD空闲函数
void wait_enable(void)
{
lcd_busy_ddr&=~busy;//设置busy口为输入
lcd_control_port&=~lcd_RS;//RS=0
lcd_control_port|=lcd_RW;//RW=1
NOP();
lcd_control_port|=lcd_EN;//E=1
while(lcd_busy_pin&busy);//等待LCD_DB7为0
lcd_control_port&=~lcd_EN;//重设E=0
lcd_busy_ddr|=busy;//设置busy口为输出
}

//指定位置显示一个字符:第一行位置0~15,第二行16~31
//显示一个字符函数
void display_a_char(unsigned char position,unsigned char char_data)//参数position指定位置0~31,char_data为要显示的字符
{
unsigned char position_tem;
if(position=0x10)
position_tem=position+0xb0;
else
position_tem=position+0x80;
lcd_write_command(position_tem,1);
lcd_write_data(char_data);
}

//指定一行显示连续字符串:0显示在第一行,1显示在第二行,注字符串不能长于16个字符
//显示一行连续字符串函数
void display_a_string(unsigned char col,unsigned char *ptr)//参数col指定行,*ptr指字符串数组的首指针