lcd_a.c

12864滚动显示汉字,驱动芯片是ST7920

#include "Main.h"
#include "Port.h"

#include "LCD_A.h"
#include "Delay_T0.h"



extern char LCD_data_G[LCD_LINES][LCD_CHARACTERS+1] ;


static void LCD_Send_Byte(const tByte, const bit) ;

static void LCD_SetDDRAM(tByte);  
static void LCD_Delay(void);

extern char   str0[];


#define LCD_DISPLAY_OFF_CURSOR_OFF_BLINKING_OFF 0x08
#define LCD_DISPLAY_ON_CURSOR_OFF_BLINKING_OFF 0x0C

#define LCD_INC_ADDR_NO_SCROLL 0x06
#define LCD_CURSOR_OFF 0x08
#define LCD_DISPLAY_ON 0x04
#define LCD_CLEAR_DISPLAY 0x01
#define LCD_4BIT_2LINE_5x8FONT 0x28  




void LCD_Init(const bit TURN_DISPLAY_ON)
   {
   tByte loop;
   tByte l,c;

   Hardware_Delay_T0(10);  

   // Set up the LCD port
   LCD_D4 = 1;
   LCD_D5 = 1;
   LCD_D6 = 1;
   LCD_D7 = 1;

   LCD_RS = 1;
   LCD_EN = 1;    

   Hardware_Delay_T0(10);  

   LCD_RS = 0;
   LCD_EN = 0;    

   // Now wait for the display to initialise
   // - data sheet says at least 40 ms
   Hardware_Delay_T0(100);

   // Data sheet says send this instruction 3 times...
   for (loop = 0; loop < 3; loop++)
      {
      // Using a 4-bit bus, 2 display lines and a 5x7 dot font
      LCD_Send_Byte(LCD_4BIT_2LINE_5x8FONT,0);  
      Hardware_Delay_T0(1);
      }
   
   // Turn the display off and the cursor off and blinking off
   LCD_Send_Byte(LCD_DISPLAY_OFF_CURSOR_OFF_BLINKING_OFF,0); 
   Hardware_Delay_T0(1);
   
   // Clear the display
   LCD_Send_Byte(LCD_CLEAR_DISPLAY,0); 
   Hardware_Delay_T0(1);

   // Invisible cursor (dummy function call to avoid library error)
   LCD_Control_Cursor(0,0,0);
   Hardware_Delay_T0(1);

   // Clear the display
   LCD_Send_Byte(LCD_CLEAR_DISPLAY,0); 
   Hardware_Delay_T0(1);

   if (TURN_DISPLAY_ON)
      {
      // Increment display address for each character but do not scroll
      LCD_Send_Byte(LCD_INC_ADDR_NO_SCROLL,0); 
      Hardware_Delay_T0(1);

      // Update all characters in the display
      for (l = 0; l < LCD_LINES; l++)
          {
          for (c = 0; c < LCD_CHARACTERS; c++)
              {
              LCD_data_G[l][c] = '*';
              LCD_Update();
              Hardware_Delay_T0(1);
              } 
          }
  //    LCD_Send_Byte(LCD_DISPLAY_ON_CURSOR_OFF_BLINKING_OFF,0); 
  //    Hardware_Delay_T0(1);
      }      
   }



void LCD_Update(void) 
   {

	tByte Character,Line;
	tByte	Data;	
	
	for(Line=0;Line<2;Line++)
		for(Character=0;Character<16;Character++)
		{
		 	if (Line == 0)
		    {
    			LCD_SetDDRAM(0x00 + Character);  // First line
			}
		  	else
		    {
	    		LCD_SetDDRAM(0x40 + Character);  // Second line
		    }

			   Data = LCD_data_G[Line][Character];
		       LCD_Send_Byte(Data,1);
			}

}


//不太优化,但是很灵活.DATA_FLAG=0为写入命令，DATA_FLAG=1为写入数据
void LCD_Send_Byte(const tByte DATA, const bit DATA_FLAG) 
   {


   LCD_D4 = 0;
   LCD_D5 = 0;
   LCD_D6 = 0;
   LCD_D7 = 0;
   LCD_RS = DATA_FLAG; // Data register
   LCD_EN = 0;
   LCD_Delay();

   // Write the data (high nybble)
   LCD_D4 = ((DATA & 0x10) == 0x10);
   LCD_D5 = ((DATA & 0x20) == 0x20);
   LCD_D6 = ((DATA & 0x40) == 0x40);
   LCD_D7 = ((DATA & 0x80) == 0x80); 

   LCD_Delay();
   LCD_EN = 1; 
   LCD_Delay();
   LCD_EN = 0;
   LCD_Delay();


   LCD_D4 = 0;
   LCD_D5 = 0;
   LCD_D6 = 0;
   LCD_D7 = 0;
   LCD_RS = DATA_FLAG;
   LCD_EN = 0;
   LCD_Delay();


   LCD_D4 = ((DATA & 0x01) == 0x01);
   LCD_D5 = ((DATA & 0x02) == 0x02);
   LCD_D6 = ((DATA & 0x04) == 0x04);
   LCD_D7 = ((DATA & 0x08) == 0x08);

   LCD_Delay();
   LCD_EN = 1; 
   LCD_Delay();
   LCD_EN = 0;
   LCD_Delay();   
   } 


void LCD_Control_Cursor(const bit VISIBLE, const bit BLINKING, 
                        const tByte ADDRESS) 
   {
   // Cursor / blinking appears at current DDRAM address 
   // - use SetDDRAM() to alter the cursor position
   tByte Command = 0x0C;  

   if (VISIBLE) 
      {
      Command |= 0x02;
      }

   if (BLINKING) 
      {
      Command |= 0x01;
      }

   LCD_Send_Byte(Command,0);
   LCD_SetDDRAM(ADDRESS);
   }

/*------------------------------------------------------------------*-

 LCD_SetDDRAM()

 Set the DDRAM to a particular address.

 Used to determine where we write to in the LCD RAM and - thus -
 whether the text appears on Line 0, Line 1, etc.

 See text for details.

 Params: The DDRAM address we wish to write to. 

-*------------------------------------------------------------------*/
void LCD_SetDDRAM(tByte ADDRESS)
{
   ADDRESS &= 0x7f;
   ADDRESS |= 0x80;
   LCD_Send_Byte(ADDRESS,0);
}



void LCD_Delay(void)   
{
   int x;

   x++;
   x++;
   x++;
}        



void Displayonechar( char x, char y, char DData)
{
/*
	x&=1;
	y&=15;
	if(x)
	y|=0x40;
	y|=0x80;
*/
//	LCD_Send_Byte(y,0);
//	LCD_Send_Byte(DData,1);
 //   LCD_Update();


// LCD_Send_Byte(Data,1);
/*
//memcpy(LCD_data_G[x][y],DData,1);
//LCD_Update();

*/
LCD_data_G[x][y]=DData;
LCD_Update();

}



void Displaylistchar( char x, char y,  char  DData[])
{       
    	  int l=0;
		  int j;
//		  DData="asd";
		  j=strlen(DData);
      
	 //x&=0x1;
     //y&=0xf;
    while(y<=15)
	 {
	   Displayonechar(x,y,DData[l]);
	   l++;
	   y++; 
	 } 

//memcpy(LCD_data_G[x][y],Info,length);
//LCD_Update();
}