1602.c

用AT89S51单片机控制的1602液晶屏程序

/*============================================================
        使用1602液晶显示的实验例子     明浩  2004/2/27
==============================================================
SMC1602A(16*2)模拟口线接线方式
连接线图: 
       ---------------------------------------------------
       |LCM-----51   | LCM-----51   | LCM------51      |
       --------------------------------------------------|
       |DB0-----P1.0 | DB4-----P1.4 | RW-------P2.0    |
       |DB1-----P1.1 | DB5-----P1.5 | RS-------P2.1    |
       |DB2-----P1.2 | DB6-----P1.6 | E--------P2.2    |
       |DB3-----P1.3 | DB7-----P1.7 | VLCD接1K电阻到GND|
       ---------------------------------------------------



[注:AT89S51使用12M晶振]
=============================================================*/

#include <reg51.h>
#define uchar unsigned char
#define uint  unsigned int
#define LCM_Data  P1
#define Busy    0x80 //用于检测LCM状态字中的Busy标识
sbit LCM_RW = P2^1; //定义引脚
sbit LCM_RS = P2^0;
sbit LCM_E  = P2^2;



void WriteDataLCM(unsigned char WDLCM);
void WriteCommandLCM(unsigned char WCLCM,BuysC);
unsigned char ReadDataLCM(void);
unsigned char ReadStatusLCM(void);
void LCMInit(void);
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData);
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData);
void delay(void);
void Delay5Ms(void);
void Delay400Ms(void);

unsigned char code cdle_net[] = {" www.cdle.net  www.cumt.edu.cn"};


void main(void)
{
 Delay400Ms(); //启动等待，等LCM讲入工作状态
 LCMInit(); //LCM初始化

 DisplayListChar(0, 0, cdle_net);
 while(1);
}

//写数据
void WriteDataLCM(unsigned char WDLCM)
{
 ReadStatusLCM(); //检测忙
 LCM_RS = 1;
 LCM_RW = 0;
 LCM_E = 0; 	//若晶振速度太高可以在这后加小的延时
 LCM_E = 0; 	//延时
 LCM_Data = WDLCM;
 LCM_E = 1;
 delay();	
 LCM_E = 0;	  
}

//写指令
void WriteCommandLCM(uchar WCLCM,BuysC) //BuysC为0时忽略忙检测
{
 if (BuysC) ReadStatusLCM(); //根据需要检测忙
 LCM_RS = 0;
 LCM_RW = 0; 
 LCM_E = 0;
 LCM_E = 0;
 LCM_Data = WCLCM;
 LCM_E = 1;
 delay();
 LCM_E = 0; 
}

//读数据
uchar ReadDataLCM(void)
{
 uchar DATA;
 LCM_RS = 1; 
 LCM_RW = 1;
 LCM_E = 0;
 LCM_E = 0;
 LCM_E = 1;
 DATA = LCM_Data;
 delay();
 LCM_E = 0;
 return(DATA);
}

//读状态
uchar ReadStatusLCM(void)
{
 LCM_Data = 0xFF; 
 LCM_RS = 0;
 LCM_RW = 1;
 LCM_E = 0;
 LCM_E = 1;
 while (LCM_Data & Busy); //检测忙信号
 LCM_E = 0;
 return(LCM_Data);
}

void LCMInit(void) //LCM初始化
{
 LCM_Data = 0;
 WriteCommandLCM(0x38,0); //三次显示模式设置，不检测忙信号
 Delay5Ms(); 
 WriteCommandLCM(0x38,0);
 Delay5Ms(); 
 WriteCommandLCM(0x38,0);
 Delay5Ms(); 

 WriteCommandLCM(0x38,1); //显示模式设置,开始要求每次检测忙信号
 WriteCommandLCM(0x08,1); //关闭显示
 WriteCommandLCM(0x01,1); //显示清屏
 WriteCommandLCM(0x06,1); // 显示光标移动设置
 WriteCommandLCM(0x0C,1); // 显示开及光标设置
}

//按指定位置显示一个字符
void DisplayOneChar(uchar X, uchar Y, uchar DData)
{
 Y &= 0x1;
 X &= 0xF; 				//限制X不能大于15，Y不能大于1
 if (Y) X |= 0x40; 		//当要显示第二行时地址码+0x40;
 X |= 0x80; 			//算出指令码
 WriteCommandLCM(X, 0); //这里不检测忙信号，发送地址码
 WriteDataLCM(DData);
}

//按指定位置显示一串字符
void DisplayListChar(uchar X, uchar Y, uchar code *DData)
{
 unsigned char ListLength;

  ListLength = 0;
 Y &= 0x1;
 X &= 0xF; 											//限制X不能大于15，Y不能大于1
 while (DData[ListLength]<0x20) 					//若到达字串尾则退出
  {
   if (X <= 0xF) 									//X坐标应小于0xF
    {
     DisplayOneChar(X, Y, DData[ListLength]); 		//显示单个字符
     ListLength++;
     X++;
    }
	else if (X == 0X10) 
	{
	 Y = 1;
	 X = 0;
	}

  }
}

void delay(void)
{
	uchar i;
	i++;
}

//5ms延时
void Delay5Ms(void)
{
 unsigned int TempCyc = 5552;
 while(TempCyc--);
}

//400ms延时
void Delay400Ms(void)
{
 unsigned char TempCycA = 5;
 unsigned int TempCycB;
 while(TempCycA--)
 {
  TempCycB=7269;
  while(TempCycB--);
 };
}