www.pudn.com > rs485(full).rar > lcd2.c
/***************************************************************************/
/* Lcd.c LCD interface routines */
/* Version : 2.1. for PIC16F87x */
/* */
/* J. Winpenny 1/8/2000 */
/* */
/* */
/* Mode : HD44780 type LCD displays */
/* */
/* */
/* Notes : Updated version */
/* to allow greater adaptability to different displays */
/* */
/***************************************************************************/
#include "lcd2.h"
/* Definitions for the LCD interface */
#define PORT_D_CONFIG 0x00
#define LCD_SEL 3 /* Port A bit 3 ( Enables LCD ) */
#define LCD_WR 2 /* Port A bit 2 ( Logic 0 = Write ) */
#define LCD_RS 1 /* Port A bit 1 ( Register select ) */
#define LCD_DATA PORTD /* The port the lcd data bus is connected to */
#define LCD_CONTROL PORTD /* The port the lcd control bus is connected to */
#define BUSY_BIT 7
#define BUSY_MASK 0x80
#define LCD_DATA_4 4 /* LCD BIT 0 */
#define LCD_DATA_5 5 /* LCD BIT 1 */
#define LCD_DATA_6 6 /* LCD BIT 2 */
#define LCD_DATA_7 7 /* LCD BIT 3 */
#define LCD_LINE_LEN 16
/************************************************************/
/* LCD Commands ( Refer to LCD Data Sheet ) */
/* Standard command should work with most common devices */
/************************************************************/
#define clear_lcd 0x01 /* Clear Display */
#define return_home 0x02 /* Cursor to Home position */
#define entry_mode 0x06 /* Normal entry mode */
#define entry_mode_shift 0x07 /* - with shift */
#define system_set_8_bit 0x38
/* 8 bit data mode 2 line ( 5x7 font ) */
#define system_set_4_bit 0x28
/* 4 bit data mode 2 line ( 5x7 font ) */
#define display_on 0x0c /* Switch ON Display */
#define display_off 0x08 /* Cursor plus blink */
#define set_dd_line1 0x80 /* Line 1 position 1 */
#define set_dd_line2 0xC0 /* Line 2 position 1 */
#define set_dd_ram 0x80 /* Line 1 position 1 */
#define write_data 0x00 /* With rs = 1 */
#define cursor_on 0x0E /* Switch Cursor ON */
#define cursor_off 0x0C /* Switch Cursor OFF */
char Modeflags, line;
/***********************************/
/* Setup the lcd device */
/***********************************/
void LCDSetup(void)
{
/* Reset the LCD */
ModeFlags = 0; /* Default to Function Mode */
Write_8_Bit( system_set_4_bit ); /* This sequence resets the LCD */
delay_ms(5);
Write_8_Bit( system_set_4_bit );
Delay();
Write_8_Bit( system_set_4_bit );
Delay();
LcdWrite( system_set_4_bit );
LcdWrite( display_on );
LcdWrite( clear_lcd );
LcdWrite( entry_mode );
LcdWrite( set_dd_ram );
ModeFlags = 1; /* Data Mode */
}
/***********************************/
/* Put LCD in Function Mode */
/***********************************/
void FunctionMode(void)
{
BIT_CLEAR( ModeFlags, 0 ); /* Save Mode */
BIT_CLEAR( LCD_CONTROL, LCD_RS );
}
/***********************************/
/* Put LCD in Data Mode */
/***********************************/
void DataMode(void)
{
BIT_SET( ModeFlags, 0 ); /* Save Mode */
BIT_SET( LCD_CONTROL, LCD_RS );
}
/***********************************/
/* Write a single byte to the LCD */
/* 8 Bit Mode */
/***********************************/
void Write_8_Bit( char dh )
{
BIT_CLEAR( dh, LCD_WR ); /* Write mode */
BIT_CLEAR( dh, LCD_RS ); /* Function mode */
BIT_CLEAR( dh, LCD_SEL);
//LCD_CONTROL = 0;
BIT_CLEAR( dh, LCD_SEL ); /* de-select LCD */
delay_ms(1);
LCD_DATA = dh; /* Setup data */
#asm
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
#endasm
BIT_SET( LCD_CONTROL, LCD_SEL ); /* Select LCD */
Delay();
BIT_CLEAR( LCD_CONTROL, LCD_SEL ); /* de-select LCD */
Delay();
}
/***********************************/
/* Write a single byte to the LCD */
/* 4 Bit Mode */
/***********************************/
void LcdWrite(char dl )
{
char e;
e = dl; /* Save lower 4 bits */
/*********************************** Output Upper 8 bits ******************************/
BIT_CLEAR( dl, LCD_WR ); /* Write mode */
if ( ( ModeFlags & 0x01 ) == 0 )
BIT_CLEAR( dl, LCD_RS ); /* Function mode */
else
BIT_SET( dl, LCD_RS ); /* Data mode */
BIT_CLEAR( dl, LCD_SEL);
LCD_DATA = dl; /* Setup data */
Delay();
BIT_SET( LCD_CONTROL, LCD_SEL); /* Select LCD */
Delay();
BIT_CLEAR( LCD_CONTROL, LCD_SEL ); /* de-select LCD */
dl = e; /* Restore lower 4 bits */
dl <<= 4;
/*********************************** Output Lower 8 bits ******************************/
BIT_CLEAR( dl, LCD_WR ); /* Write mode */
if ( ( ModeFlags & 0x01 ) == 0 )
BIT_CLEAR( dl, LCD_RS ); /* Function mode */
else
BIT_SET( dl, LCD_RS ); /* Data mode */
BIT_CLEAR( dl, LCD_SEL);
LCD_DATA = dl; /* Setup data */
#asm
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
#endasm
BIT_SET( LCD_CONTROL, LCD_SEL); /* Select LCD */
Delay();
BIT_CLEAR( LCD_CONTROL, LCD_SEL ); /* de-select LCD */
Delay();
}
/***********************************/
/* LCD timing delay */
/* Adjust for your LCD Display */
/***********************************/
void Delay(void)
{
delay_ms(2);
}
/***********************************/
/* Clear LCD Screen */
/***********************************/
void Clear(void)
{
FunctionMode();
LcdWrite(clear_lcd);
DataMode();
}
/***********************************/
/* Set the cursor position */
/***********************************/
void SetPos(char Pos)
{
FunctionMode();
LcdWrite( Pos );
DataMode();
}
/***********************************/
/* Set Position to line 1 */
/***********************************/
void Line1(void)
{
line = 1;
FunctionMode();
LcdWrite( set_dd_line1 );
DataMode();
}
/***********************************/
/* Set Position to line 2 */
/***********************************/
void Line2(void)
{
line = 2;
FunctionMode();
LcdWrite( set_dd_line2 );
DataMode();
}
/*******************************************/
/* Clear Line 1 */
/*******************************************/
void ClearLine1(void)
{
char c;
Line1();
for( c = 0; c < LCD_LINE_LEN; c++ )
{
LcdWrite(' ');
}
Line1();
}
/*******************************************/
/* Clear Line 2 */
/*******************************************/
void ClearLine2(void)
{
char c;
Line2();
for( c = 0; c < 16; c++ )
{
LcdWrite(' ');
}
Line2();
}
/*******************************************/
/* Write a const string to the LCD */
/*******************************************/
void WriteString( char *lcdptr )
{
char c;
c = 0;
// Check for end of string
while( lcdptr[c] != 0 )
{
// Don't display CR's
if ( lcdptr[c] == 13 ) break;
LcdWrite( lcdptr[c++] );// Display on LCD
}
}