fun.c

lcd1602编程资料。包括8位和4位口的c语言程序。当单片机口不够时可用4位接法

#include <reg51.h>
#include <intrins.h>
#include "lcd1602.h"

 
void delay (uchar times)			 //delay times ms
{
  uchar i = 0;
  while (times --)
  {
    for (i = 0; i < 120; i++);
  }

}

bit bBusy()
{
  bit result;
  RS = 0; RW = 1;      // read the AC and BF
  EN = 1;			   // generate a high level to read

  _nop_();  _nop_(); 
  _nop_();  _nop_();

  result = (bit)(P0 & 0x80);  //-----important------ *the four higher bits*

  // the lower four bits has been ignored //

  EN = 0;

  return result;

}

void wr_byte(bit bcmd, uchar cmd)
{
  uchar Hcmd, Lcmd;
  Hcmd = cmd & 0xF0;
  Lcmd = (cmd << 4) & 0xF0;

  while (bBusy());     // wait if the lcd is busy

  if (bcmd)			   // if it's  cmd, RS = 0;
    RS = 0;
  else				   // if it's data, RS = 1;
    RS = 1;

  RW = 0;	       	   // set  R/W = 0
//  EN = 0;			   // this step is ignorable

  _nop_();  _nop_(); 
  _nop_();  _nop_();

  P0 = Hcmd;	   	// prepare the higher four bits of the valid data
  EN = 1;				// set E = 1

  _nop_();  _nop_(); 
  _nop_();  _nop_();

  EN = 0;				// set E = 0, generate a falling edge to write

  _nop_(); _nop_();  
  _nop_(); _nop_();

  P0 = Lcmd;	   	// prepare the lower four bits of the valid data
  EN = 1;				// set E = 1

  _nop_();  _nop_(); 
  _nop_();  _nop_();

  EN = 0;				// set E = 0, generate a falling edge to write

  _nop_(); 

}


void ini_lcd1602(void)
{
  delay (10);
  
/* Function Set */
  wr_byte (1, 0x28);			 	// 2 lines; 5*7 font; 4 bits
  delay (5);
  wr_byte (1, 0x28);				// repeat the Function Set
  delay (5);

    
 /* --Display on/off-- */
  wr_byte (1, 0x0c);				// Display: on; Cursor: on; Blink: on;

/* --Display clear-- */
  wr_byte (1, 0x01);				// display clear;
  delay (5);
  
/* --Entry mode set-- */	   // I/D: incremental; SH: 0;
  wr_byte (1, 0x06);

}

void wr_byte_ram (bit bDDram, uchar addr, uchar ch)
{
  if (bDDram)				  // write data to DDRAM
     wr_byte (1, addr | 0x80);
  else						  // write data to CGRAM
     wr_byte (1, addr | 0x40);

  wr_byte (0, ch);		
}

void wr_length_ram (bit bDDram, uchar addr, uchar *pch, uchar len)
{
  uchar i = 0;

  if (bDDram)				  // write data to DDRAM
    wr_byte (1, addr | 0x80);
  else						  // write data to CGRAM
    wr_byte (1, addr | 0x40);

  for (; i < len; i++)
  {
    wr_byte (0, *pch);		  // the AC will increase/decrease automatically
	pch ++;
  }

}