part2.2_2.c

郭天祥十天学会单片机_随书光盘文件

#include <reg52.h>    		//52系列单片机头文件
#define uchar unsigned char
#define uint unsigned int 
sbit dula=P2^6;		//申明U1锁存器的锁存端
sbit wela=P2^7;		//申明U2锁存器的锁存端
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void delayms(uint xms)				
{
	uint i,j;
	for(i=xms;i>0;i--)		      //i=xms即延时约xms毫秒
		for(j=110;j>0;j--);
}
void display(uchar num)
{
	P0=table[num]; //显示函数只送段选数据
	dula=1;
	dula=0;
}
void matrixkeyscan()
{
	uchar temp,key;
    P3=0xfe;
    temp=P3;
    temp=temp&0xf0;
    if(temp!=0xf0)
    {
      delayms(10);
	  temp=P3;
	  temp=temp&0xf0;
      if(temp!=0xf0)
      {
        temp=P3;
        switch(temp)
        {
          case 0xee:
               key=0;
               break;
          case 0xde:
               key=1;
               break;
          case 0xbe:
               key=2;
               break;
          case 0x7e:
               key=3;
               break;
         }
         while(temp!=0xf0)
         {
           temp=P3;
           temp=temp&0xf0;
         }
        display(key);
      }
    }
    P3=0xfd;
    temp=P3;
    temp=temp&0xf0;
    if(temp!=0xf0)
    {
      delayms(10);
      temp=P3;
      temp=temp&0xf0;
      if(temp!=0xf0)
      {
        temp=P3;
        switch(temp)
        {
          case 0xed:
               key=4;
               break;
          case 0xdd:
               key=5;
               break;
          case 0xbd:
               key=6;
               break;
          case 0x7d:
               key=7;
               break;
         }
         while(temp!=0xf0)
         {
           temp=P3;
           temp=temp&0xf0;
         }
         display(key);
      }
      }
    P3=0xfb;
    temp=P3;
    temp=temp&0xf0;
    if(temp!=0xf0)
    {
      delayms(10);
   	  temp=P3;
      temp=temp&0xf0;
      if(temp!=0xf0)
      {
        temp=P3;
        switch(temp)
        {
          case 0xeb:
               key=8;
               break;
          case 0xdb:
               key=9;
               break;
          case 0xbb:
               key=10;
               break;
          case 0x7b:
               key=11;
               break;
         }
         while(temp!=0xf0)
         {
           temp=P3;
           temp=temp&0xf0;
         }
        display(key);
      }
      }
    P3=0xf7;
    temp=P3;
    temp=temp&0xf0;
    if(temp!=0xf0)
    {
      delayms(10);
      temp=P3;
      temp=temp&0xf0;
      if(temp!=0xf0)
      {
        temp=P3;
        switch(temp)
        {
          case 0xe7:
               key=12;
               break;
          case 0xd7:
               key=13;
               break;
          case 0xb7:
               key=14;
               break;
          case 0x77:
               key=15;
               break;
         }
         while(temp!=0xf0)
         {
           temp=P3;
           temp=temp&0xf0;
         }
        display(key);
      }
    }
}
void main()
{
	P0=0;  //关闭所有数码管段选
	dula=1;
	dula=0;
	P0=0xc0;//位选中所有数码管
	wela=1;
	wela=0;
  while(1)
  {
	matrixkeyscan();//不停调用键盘扫描程序
  }
}