lcd4bit._c

C语言开发使LCD显示汉字程序,采用自带汉字库的LCD模块.

/*
**  File:       LCD4BITS.C
**
**  Purpose:    LCD Routines for 4 bit I/O (D4->D7+E+RS)
**              D4-D7 is connected on PORTB4-7
**              E is connected on PORTB3
**              RS is connected on PORTB2
**
**  Chip:		ATMega48
**
**  Version:    1.0.0, 23:rd of May 2003
**
**  Author:     Lars Wictorsson
**              LAWICEL / SWEDEN
**              http://www.lawicel.com   [e-mail]
**
**  Copyright:  The copyright to the computer program(s) herein is the
**              property of LAWICEL HB, Sweden. The program(s) may be used
**              and/or copied only with the written permission of LAWICEL HB
**              in accordance with the terms and conditions stipulated in
**              the agreement/contract under which the program(s) have been
**              supplied.
**
**	Remarks:	This program is tested with ICCAVR version 6.27A.
**
**  History:    2003-05-23  1.0.0   Created (LWI)
*/

#include <iom48v.h>
#include <macros.h>

//void waitMS(unsigned long);

#define WASTE               waste_lcd()

#define LCD_E_SET           PORTB |= 0x40		   //PORTB.3-LCD ENABLE
#define LCD_E_CLR           PORTB &= ~0x40		   //PORTB.3-LCD DISABLE
#define LCD_RS_SET          PORTB |= 0x80 		   //PORTB.2-DISPLAY DATA
#define LCD_RS_CLR          PORTB &= ~0x80		   //PORTB.2-INSTRCTION
//**              E is connected on PORTB3
//**              RS is connected on PORTB2
#define xtal 8
#define DELAY               for (del = 0; del < 16; del++)

long del;

void waste_lcd(void)
{
}
   
void delay_1ms(void)
{
 unsigned int i;
 for(i=1;i<(unsigned int)(xtal*143-2);i++);
}

void waitms(unsigned int n)
{
 unsigned int i=0;
 while(i<n)
  {
   delay_1ms();
   i++;
  }
}

void LCD4_WR4bits(unsigned char c)
{
    c &= 0x0F;//屏蔽高四位
    c = c << 4;//移入高四位
    LCD_E_SET;
    WASTE;
    PORTB &= 0x0F;
    PORTB |= c;
    WASTE;
    LCD_E_CLR;
    WASTE;
}

void LCD4_Init(void)
{
    waitms(15);                     // Wait on power up 15mS
    LCD_RS_CLR;
    DELAY;
    
    LCD4_WR4bits( 0x03);            // Function Set 8bit
    waitms(5);

    LCD4_WR4bits( 0x03);            // Function Set 8bit
    waitms(5);

    LCD4_WR4bits( 0x03);            // Function Set 8bit
    waitms(5);

    LCD4_WR4bits( 0x02);            // Function Set 4bit
    waitms(5);

    LCD4_WR4bits( 0x02);            // Function Set
    LCD4_WR4bits( 0x08);
    DELAY;

    LCD4_WR4bits( 0x00);            // Display ON/OFF
    LCD4_WR4bits( 0x0C);            // Display ON, Curson OFF, Blink OFF
    DELAY;
    
    LCD4_WR4bits( 0x00);            // Entry mode
    LCD4_WR4bits( 0x06);
    DELAY;

    LCD_RS_SET;
    waitms(5);
}

void LCD4_Clear(void)
{
    LCD_RS_CLR;
    DELAY;
    LCD4_WR4bits( 0x00);    // Clear Display
    LCD4_WR4bits( 0x01);
    DELAY;
    LCD_RS_SET;
    waitms(5);
}

void LCD4_Home(void)
{
    LCD_RS_CLR;
    DELAY;
    LCD4_WR4bits( 0x00);
    LCD4_WR4bits( 0x02);
    DELAY;
    LCD_RS_SET;
    waitms(5);
}

void LCD4_Home2(void)
{
    LCD_RS_CLR;
    DELAY;
    LCD4_WR4bits( 0x0C);    // Clear Display
    LCD4_WR4bits( 0x00);
    DELAY;
    LCD_RS_SET;
    waitms(5);
}

void LCD4_PutC(unsigned char data)
{
    LCD4_WR4bits( data >> 4);
    DELAY;
    LCD4_WR4bits( data);
    DELAY;
}

void LCD4_PutC_Const(const unsigned char data)
{
    LCD4_WR4bits( data >> 4);
    DELAY;
    LCD4_WR4bits( data);
    DELAY;
}

void LCD4_PutS(unsigned char *data)
{
    unsigned char c = 0;

    while (data[c] != 0) {
        LCD4_WR4bits( data[c] >> 4);
        LCD4_WR4bits( data[c++]);
		DELAY;
    }
}
void main(void)
{
 LCD4_Init();
 LCD4_Clear();
 LCD4_Home();
 LCD4_Home2();
// LCD4_PutC(unsigned char);
// LCD4_PutC_Const(const unsigned char);
// LCD4_PutS(unsigned char *);
}