lcd.c

利用HOLTEK单片机开发的1602液晶驱动

/*=========================================================================== 
KS0070(44780) 16x2 字符液晶屏驱动演示程序总线方式 晓奇
=============================================================================
连接线图: 
LCM-------51 LCM-------51 LCM--------51
DB0-----PB.0 DB4-----PB.4 RS-------PA.0
DB1-----PB.1 DB5-----PB.5 RW-------PA.1
DB2-----PB.2 DB6-----PB.6 E--------PA.2
DB3-----PB.3 DB7-----PB.7 

[注]:HT46R24的晶振频率为12MHz
============================================================================*/

//========= 变量类型标识的宏定义，大家都喜欢这么做 ==============
#define Uchar unsigned char
#define Uint unsigned int

// ================= LCM1602A端口地址定义 =======================
 
#define LCM_RS  	_pa0	//定义引脚
#define LCM_RW  	_pa1
#define LCM_E   	_pa2

#define Busy    	0x80 //用于检测LCM状态字中的Busy标识

#include <ht46r24.h>

void WriteDataLCM(Uchar WDLCM);
void WriteCommandLCM(Uchar WCLCM,Uchar BusyC);
Uchar ReadDataLCM(void);
Uchar ReadStatusLCM(void);
void LCMInit(void);
void Display(Uchar dd);
void DisplayOneChar(Uchar X, Uchar Y, Uchar DData);
void DisplayListChar(Uchar X, Uchar Y, Uchar *DData);
void Delay5Ms(void);
void Delay400Ms(void); 

void main(void)
{
	Uchar cdle_net[] = {"www.cdle.net"};
	Uchar email[] = {"[e-mail]"};
	Uchar temp;
	int i;
	_pac=0;
	temp=32;
	Delay400Ms();	//启动等待，等LCM讲入工作状态
	LCMInit();		//LCM初始化
	Delay5Ms();		//延时片刻(可不要)
	
	for(i=0;i<5;i++) Delay400Ms();
	DisplayListChar(0, 0, cdle_net);
	DisplayListChar(0, 1, email);
	ReadDataLCM();	//测试用句无意义

	while(1)
	{
		temp &= 0x7f; // 只显示ASCII字符
		if (temp<32)temp=32; // 屏蔽控制字符，不予显示
		Display( temp++ );
		Delay400Ms();
	}
}

//写数据
void WriteDataLCM(Uchar WDLCM)	
{
	ReadStatusLCM();	//检测忙
	_pbc=0;
	_pb = WDLCM;
	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
	//_delay(2);	//延时
	LCM_E = 1;
}

//写指令
void WriteCommandLCM(Uchar WCLCM, Uchar BusyC) //BusyC为0时忽略忙检测
{
	if (BusyC) ReadStatusLCM(); //根据需要检测忙
	_pbc=0;
	_pb = WCLCM;
	LCM_RS = 0;
	LCM_RW = 0; 
	LCM_E = 0;
	//_delay(2);
	LCM_E = 1; 
}

//读数据
Uchar ReadDataLCM(void)
{
	_pbc=0xff;
	LCM_RS = 1; 
	LCM_RW = 1;
	LCM_E = 0;
	//_delay(2);
	LCM_E = 1;
	return(_pb);
}

//读状态
Uchar ReadStatusLCM(void)
{
	_pbc = 0xff; 
	LCM_RS = 0;
	LCM_RW = 1;
	LCM_E = 0;
	LCM_E = 0;
	LCM_E = 1;
	while (_pb & Busy); //检测忙信号
	return(_pb);
}

void LCMInit(void) //LCM初始化
{
	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
}

//演示一行连续字符串，配合上位程序演示移动字串
void Display( Uchar dd ) 
{
	Uchar i;

	for (i=0;i<8;i++)
	{
		DisplayOneChar(i,1,dd++);
		dd &= 0x7f;
		if (dd<32) dd=32;
	}
}

//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 *DData)
{
	Uchar 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++;
		}
	}
}

//指令周期为4*1/12=1/3 us
void Delay5Ms(void)		// 短延时
{
	_delay(15000);
}


void Delay400Ms(void)	//长延时
{
	int i;
	for(i=0;i<20;i++)
	{
		_delay(60000);
	}
}


//////////////////////////////////////////////////////////////////////////////