lcd._c

MEGA16单片机程序包2

//编译器：ICC-AVR 
//日期: 2007-4-13 20:29:57 
//目标芯片 : ATmega16 
//时钟: 8.0000Mhz 
//版本：VISION 2.0
/*
LCD引脚定义 
1---GND  
2---VCC 
3---VO 
4---RS 
5---RW 
6---EN 
7到14--D0-D7 
15--背景灯+ 
16--背景灯-
 
下面是AVR与LCD连接信息 
PA1 ->RS 
PA0 ->EN 
GND  ->RW 
PA4 ->D4 
PA5 ->D5 
PA6 ->D6 
PA7 ->D7 
*/

//#include <iom16v.h>
//#include <macros.h>
#include "main.h"

#define uchar unsigned char
#define uint unsigned int

#define LCD_EN_PORT    PORTA   //数据寄存器,以下2个要设为同一个口 
#define LCD_EN_DDR     DDRA    //数据方向寄存器
#define LCD_RS_PORT    PORTA   //以下2个要设为同一个口 
#define LCD_RS_DDR     DDRA 
#define LCD_DATA_PORT  PORTA   //以下3个要设为同一个口 
#define LCD_DATA_DDR   DDRA    //一定要用高4位 
#define LCD_DATA_PIN   PINA    //端口输入引脚
#define LCD_RS         (1<<PA1) //0x04   portA1       out 
#define LCD_EN         (1<<PA0) //0x08   portA0       out 
#define LCD_DATA       ((1<<PA4)|(1<<PA5)|(1<<PA6)|(1<<PA7)) //0xf0   portA4/5/6/7 out 



void LCD_init(void); 
void LCD_en_write(void); 
void LCD_write_command(uchar command); 
void LCD_write_data(uchar data); 
void LCD_set_xy (uchar x, uchar y); 

void delay(uint n)       //N ms延时函数 
  { 
   uint i;
   while(n--) 
   for (i=0;i<125;i++); 
  } 
  
void LCD_init(void)         //液晶初始化 
{ 
  LCD_DATA_DDR|=LCD_DATA;   //数据口方向为输出 
  LCD_EN_DDR|=LCD_EN;       //设置EN方向为输出 
  LCD_RS_DDR|=LCD_RS;       //设置RS方向为输出 
  LCD_write_command(0x28);  
  LCD_en_write(); 
  delay(40); 
  LCD_write_command(0x28);  //4位显示 
  LCD_write_command(0x0c);  //显示开 
  LCD_write_command(0x01);  //清屏 
  delay(2); 
} 

void LCD_en_write(void)  //液晶使能 
{ 
  LCD_EN_PORT|=LCD_EN; 
  delay(1); 
  LCD_EN_PORT&=~LCD_EN; 
} 

void LCD_write_command(uchar command) //写指令 
{ 
  delay(16); 
  LCD_RS_PORT&=~LCD_RS;        //RS=0 
  LCD_DATA_PORT&=0X0f;         //清高四位 
  LCD_DATA_PORT|=command&0xf0; //写高四位 
  LCD_en_write(); 
  command=command<<4;          //低四位移到高四位 
  LCD_DATA_PORT&=0x0f;         //清高四位 
  LCD_DATA_PORT|=command&0xf0; //写低四位 
  LCD_en_write(); 
   
} 

void LCD_write_data(uchar data) //写数据 
{ 
  delay(16); 
  LCD_RS_PORT|=LCD_RS;       //RS=1 
  LCD_DATA_PORT&=0X0f;       //清高四位 
  LCD_DATA_PORT|=data&0xf0;  //写高四位 
  LCD_en_write(); 
  data=data<<4;               //低四位移到高四位 
  LCD_DATA_PORT&=0X0f;        //清高四位 
  LCD_DATA_PORT|=data&0xf0;   //写低四位 
  LCD_en_write(); 
} 


void LCD_set_xy( uchar x, uchar y )  //写地址函数 
{ 
    uchar address; 
    if (y == 0) address = 0x80 + x; 
    else   address = 0xc0 + x; 
    LCD_write_command( address); 
} 
   
void LCD_write_string(uchar X,uchar Y,uchar *s) //列x=0~15,行y=0,1 
{ 
    LCD_set_xy( X, Y ); //写地址     
    while (*s)  // 写显示字符 
    { 
      LCD_write_data( *s ); 
      s ++; 
    } 
       
} 

void LCD_write_char(uchar X,uchar Y,uchar data) //列x=0~15,行y=0,1 
{ 
  LCD_set_xy( X, Y );      //写地址 
  LCD_write_data( data); 
   
} 

void init_devices(void) 
{ 
  CLI();             //disable all interrupts 
  LCD_init(); 
  MCUCR = 0x00; 
  GICR  = 0x00; 
  TIMSK = 0x00;      // r interrupt sources 
  SEI();            //re-enable interrupts 
}