键盘实验.c

使用单片机keilc51编程,利用单片机定时功能读取键盘扫描码,从而利用数码管显示.

#include <reg52.h>
#include <intrins.h>
sbit key_data=P3^1;		
sbit key_clk=P3^2;	//定义键盘接口的时钟脚
//sbit RELAY=P1^0;		//继电器
sbit RELAY=P1^1;
bit BF=0;
unsigned char code table[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0x88,0x83,0xC6,0xA1,0x86,0x8E};
unsigned char keyv=0;			//变量为常量的索引
unsigned int intNum=0;			//计数接收个数
unsigned char key_up=1;			//检测按键按下否

void ldedata(unsigned char scandata);//数据处理

void main(void)     //入口函数
{


	EA=1;			//首先开启总中断
	EX0=1;  		//开启外部中断 0
	IT0=1;        // 设置成 下降沿触发方式
	P2=0;
	do{					//循环
		if(BF)
			ldedata(keyv);
		else
			EA=1;
	}
	while(1);	
}

void key_scan()   interrupt 0
{    //外部中断 0 					
	if((intNum>0)&&(intNum<9)){
		keyv=keyv>>1;
		if(key_data)
			keyv=keyv|0x80;				
	}
	intNum++;
	while(!key_clk);
	if(intNum>10){
		intNum=0;
		BF=1;
		EA=0;			//等待处理完键值再开启
	}


}

void ldedata(unsigned char scandata)
{

	if(!key_up)	//键盘松开时
	{
	
		 switch(scandata){
		 case 0x66:
			key_up=1;
			break;
		   case 0x69:	
             	P0=table[1];
					break;
		 	case 0x72:	
             	P0=table[2];
					break;
		case 0x7a:	
           P0=table[3];
			  
			break;
		 	case 0x7d:	
             	P0=table[9];
			
			break;

		 	case 0x73:	
             	P0=table[5];
					break;
		case 0x74:	
           P0=table[6];
			   
			break;
		  	case 0x7b:	
           P0=table[10];
			   
			break;
		   	case 0x79:	
           P0=table[11];
			   
			break;
		   
		default:
				

			if(scandata==0x6c)		
			   	P0=table[7];
			if(scandata==0x75){			
					P0=table[8];
			}
				if(scandata==0x6b)		
			   	 RELAY=0;
			  if(scandata==0xe0, 0x5a, 0xe0)		
			   						 
		 RELAY=1;
		}
	  }
	 
	
	else{
		key_up=0;
		switch(scandata){
		case 0x12:
			
			break;
		case 0x59:
			
			break;
		}
	}
	BF=0;	
}