1602 four wire-cvavr.txt

用CVAVR 编写的ATMEGA128的LCD 1602 显示程序,四总线,占用了PC口,P7-P2 共占用了6个I/O口!

PC7-PC4 接高四位数据线

VSS   接地 VDD接V+

PC 3接 E

PC2接 RS

R/W接 地
#include <mega128.h>
#include<delay.h>
#define LCD_EN_PORT     PORTC
#define LCD_RW_PORT     PORTC
#define LCD_RS_PORT     PORTC
#define LCD_DATA_PORT   PORTC
#define LCD_DATA_DDR    DDRC
#define LCD_DATA_PIN    PINC
#define LCD_EN          0x08    //portd7         out
#define LCD_RS          0x04    //portc6         out
#define LCD_DATA        0xff    //porta4/5/6/7    out

/*--------------------------------------------------------------------------------------------------
Public function prototypes
--------------------------------------------------------------------------------------------------*/
void LCD_init          (void);
void LCD_en_write      (void);
void LCD_write_char    (unsigned command,unsigned data);
void LCD_set_xy        (unsigned char x, unsigned char y);
void LCD_write_string (unsigned char X,unsigned char Y, char flash *s);
void LCD_init(void)        //液晶初始化
{
delay_ms(5);
LCD_write_char(0x28,0);   //4位显示
LCD_write_char(0x0c,0);   //显示开
LCD_write_char(0x01,0);   //清屏
}
void LCD_write_string(unsigned char X,unsigned char Y, char flash *s)
   {
     LCD_set_xy( X, Y ); //写地址
    
     while (*s)   // 写显示字符
       {
         LCD_write_char( 0, *s );
s ++;
       }
   }
   void LCD_set_xy( unsigned char x, unsigned char y )   //写地址函数
   {
     unsigned char address;
     if (y == 0) address = 0x80 + x;
     else 
        address = 0xc0 + x;
     LCD_write_char( address, 0 );
   }
void LCD_en_write(void)   //液晶使能
{
   LCD_EN_PORT|=LCD_EN;
   delay_us(1);
   LCD_EN_PORT&=~LCD_EN;
}
void LCD_write_char(unsigned command,unsigned data) // 写数据
{
unsigned command_temp,data_temp;
command_temp=command;
data_temp=data;
delay_us(16);
if(command==0)
{
   LCD_RS_PORT|=LCD_RS;   //RS=1
   LCD_DATA_PORT&=0X0f;
   LCD_DATA_PORT|=data_temp&0xf0;   //写高四位
   LCD_en_write();
   data_temp=data_temp<<4;  
   LCD_DATA_PORT&=0X0f;
   LCD_DATA_PORT|=data_temp&0xf0;    //写低四位
   LCD_en_write();
}
else
{
   LCD_RS_PORT&=~LCD_RS;    //RS=0
   LCD_DATA_PORT&=0X0f;
   LCD_DATA_PORT|=command_temp&0xf0; //写高四位
   LCD_en_write();
   command_temp=command_temp<<4;
   LCD_DATA_PORT&=0x0f;
   LCD_DATA_PORT|=command_temp&0xf0;   //写低四位
   LCD_en_write();
   }
}
void main(void)
{
      DDRC|=LCD_DATA;    // 数据为输出
   DDRC|=LCD_RS|LCD_EN;   //置位RS.EN
      LCD_init();
      while(1)     //for循环
        {
       LCD_write_char(0x01,0);
    delay_ms(1);
          LCD_write_string(0,0,"Wellcome");
          LCD_write_string(0,1,"OURAVR!");
          delay_ms(150);
          LCD_write_string(0,0,"happy new year!");
          LCD_write_string(0,1,"tang:everfriend");
          delay_ms(150);
        }
}