keyscan.c

通过C语言控制数码管动态扫描显示

#include <reg52.h>
#define uchar unsigned char
#define uint  unsigned int

uchar code dutable[]={    //段选表
0xc0,0xf9,0xa4,0xb0,0x99,
0x92,0x82,0xf8,0x80,0x90,
0x88,0x83,0xc6,0xa1,0x86,0xbf}; 
//uchar code wetable[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0xfd};    //位选表
uchar code wetable[]={0xfe,0xfd,0xfb,0xf7};    //位选表

uchar Time_num;
uint fen,miao;
uint Set_key_num;	  //设置按钮的按下次数
sbit Set_key=P1^5;   //设置按钮
sbit Inc_key=P1^6;   //增1按钮
sbit Dec_key=P1^7;   //减1按钮

uchar num,temp;
uchar keyscan();

void delay(uchar z)
{
	uchar x,y;
	for(x=110;x>0;x--)
		for(y=z;y>0;y--);
}

////////////////////
//  数码管显示函数
void display(uint ifen,uint imiao)
{
	uint shi_fen,ge_fen,shi_miao,ge_miao;

	shi_fen = ifen/10;
	ge_fen = ifen%10;
	shi_miao = imiao/10;
	ge_miao = imiao%10;

	P2=wetable[0];
	P0=dutable[shi_fen];
	delay(1);
	
	P2=wetable[1];
	P0=dutable[ge_fen];
	delay(1);
	
	P2=wetable[2];
	P0=dutable[shi_miao];
	delay(1);

	P2=wetable[3];
	P0=dutable[ge_miao];
	delay(1);	
}


void init()
{
	P2 = 0xff;
	Time_num=0;

	fen = 12;
	miao = 02;

	TMOD=0X01;
	TH0=(65536-50000)/256;
	TL0=(65536-50000)%256;
	EA=1;
	ET0=1;
	TR0=0;	

	
}


void main()
{
	init();
	while(1)
	{
		////////////////////
		//倒计时处理
		if(Time_num == 20)
		{
			Time_num = 0;
			if(fen==0)
			{
				if(miao==0)
					;	/////////////////////////
			}
			miao--;	
			if(miao==-1)
			{
				miao=59;
				fen--;
			}
				
		}

		keyscan();

		////////////////////
		//  "设置"键按下
		if(num==1)
		{
				TR0=0; 
				if(Set_key_num>=3)   //按了3次
				{
					Set_key_num = 0;
					TR0=1;//开始倒计时	
				}
				Set_key_num++;       //次数加
		}
	
		////////////////////
		//  "增加"键按下
		if(num==2)              
		{   
			if(Set_key==1)	//按了1次，调分钟
			{
				if(fen==60)
					fen=0;
				else
					fen++;
			}
			if(Set_key==2)
			{
				if(miao==60)
					miao=0;
				else
					miao++;
			}
			
		}   
		////////////////////
		//  "降低"键按下
		if(num==3)               
		{   
			if(Set_key==1)	//按了1次，调秒钟
			{ 
				if(fen==-1)
					fen=60;
				else
					fen--;								
			}
			if(Set_key==2)
			{
				if(miao==-1)
					miao=0;
				else
					miao--;	
			}
			
		}

		display(fen,miao);	
	}
	

}


void timer0() interrupt 1
{
	TH0=(65536-50000)/256;
	TL0=(65536-50000)%256;
	Time_num++;	
}


uchar keyscan()   //4*4举证键盘接到P1口，进行以此循环判断
{
    P1=0xfe;
    temp=P1;
    temp=temp&0xf0;
    while(temp!=0xf0)
	{
		delay(5);
		temp=P1;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			temp=P1;
			switch(temp)
			{
			case 0xee:num=1;
				break;
			case 0xde:num=2;
				break;
			case 0xbe:num=3;
				break;
			case 0x7e:num=4;
				break;
			}
			while(temp!=0xf0)
			{
				temp=P1;
				temp=temp&0xf0;
			}
		}
	}
	
    P1=0xfd;
    temp=P1;
    temp=temp&0xf0;
    while(temp!=0xf0)
	{
		delay(5);
		temp=P1;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			temp=P1;
			switch(temp)
			{
			case 0xed:num=5;
				break;
			case 0xdd:num=6;
				break;
			case 0xbd:num=7;
				break;
			case 0x7d:num=8;
				break;
			}
			while(temp!=0xf0)
			{
				temp=P1;
				temp=temp&0xf0;
			}
		}
	}
	
	
    P1=0xfb;
    temp=P1;
    temp=temp&0xf0;
    while(temp!=0xf0)
	{
		delay(5);
		temp=P1;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			temp=P1;
			switch(temp)
			{
			case 0xeb:num=9;
				break;
			case 0xdb:num=10;
				break;
			case 0xbb:num=11;
				break;
			case 0x7b:num=12;
				break;
			}
			while(temp!=0xf0)
			{
				temp=P1;
				temp=temp&0xf0;
			}
		}
	}
	
	
    P1=0xf7;
    temp=P1;
    temp=temp&0xf0;
    while(temp!=0xf0)
	{
		delay(5);
		temp=P1;
		temp=temp&0xf0;
		while(temp!=0xf0)
		{
			temp=P1;
			switch(temp)
			{
			case 0xe7:num=13;
				break;
			case 0xd7:num=14;
				break;
			case 0xb7:num=15;
				break;
			case 0x77:num=16;
				break;
			}
			while(temp!=0xf0)
			{
				temp=P1;
				temp=temp&0xf0;
			}
		}
	}
	return num;	
}