小白求助，矩阵键盘检测问题

只看该作者 · 2017-3-29 19:04

void keyscan()
{
uchar temp;//
P3 = 0xf0;
temp=(P3 & 0xf0);

if(temp != 0xf0)//
{

delay(5);//
temp=P3 & 0xf0;
if(temp != 0xf0)//
{
P3 = temp | 0x0f;
keyvalue = P3;//
while((P3 = temp | 0x0f) == keyvalue);//
}
}

}

不用变量temp时，直接if(p3 & 0xf0 != 0xf0)，检测不了矩阵键盘按下是什么原因呢？

只看该作者 · 2017-3-29 20:31

按多了，会检测不到是怎么回事儿？

只看该作者 · 2017-3-29 20:32

void main()
{
   for(;;)
{

keyscan();
if(1 == key_deal(keyvalue))
{
   led1 = 0;
}
if(4 == key_deal(keyvalue))
{
   led1 = 1;
}
}
}

void keyscan()
{
uchar temp;
P3 = 0xf0;
temp=(P3 & 0xf0);
if(temp != 0xf0)// ÅÐ¶ÏÊÇ·ñÓÐ°´¼ü°´ÏÂ
{

delay(5);// Ïû¶¶
temp=P3 & 0xf0;
if(temp != 0xf0)// ÔÙ´ÎÅÐ¶Ï£¬È·¶¨ÊÇ·ñÕæµÄÓÐ°´¼ü°´ÏÂ
{
P3 = temp | 0x0f;//°Ñ¸ßËÄÎ»µÄÖµ¸³¸øP3£¬´Ó¶ø¿ÉÒÔµÃµ½Ò»¸ö°ËÎ»µÄ¼üÖµÂë
keyvalue = P3;// »ñÈ¡¼üÖµÂë
while((P3 = temp | 0x0f) == keyvalue);//ËÉÊÖ¼ì²â
}
}

}

uchar key_deal(uchar temp)//
{
uchar num = 0;
switch(temp)
{
case 0xee : num = 1;
break;
case 0xed : num = 5;
break;
case 0xeb : num = 9;
break;
case 0xe7 : num = 13;
break;

case 0xde : num = 2;
break;
case 0xdd : num = 6;
break;
case 0xdb : num = 10;
break;
case 0xd7 : num = 14;
break;

case 0xbe : num = 3;
break;
case 0xbd : num = 7;
break;
case 0xbb : num = 11;
break;
case 0xb7 : num = 15;
break;

case 0x7e : num = 4;
break;
case 0x7d : num = 8;
break;
case 0x7b : num = 12;
break;
case 0x77 : num = 16;
break;

default : ;
}

return num;
}