課程設計：矩陣鍵盤（c51，使用掃描法實現）
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//這種方法是用只用P3口的前高四位來比較，看改變了么(由于比較倉促，沒有proteus仿真，不過這是個比較經典的方法，網上有很多這個代碼，源自郭天祥的視頻和書籍)
本文引用地址：http://www.104case.com/article/201611/315828.htm#include
#define uchar unsigned char
#define uint unsigned int
sbit wela=P2^7;
sbit dula=P2^6;
uchar num,num1;
unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,
0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
void delay(uint xms)
{
uint x,y;
for(x=xms;x>0;x--)
for(y=111;y>0;y--);
}
void display(uchar num)
{
dula=1;
P1=table[num];
dula=0;
//delay(10);
}
void matrixkeyscan()
{
uchar temp,key;
P3=0xfe;//第一行
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
delay(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;//第二行
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
delay(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;//第三行
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
delay(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;//第四行
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
delay(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()
{
dula=0;
wela=1;
P1=0x00;
wela=0;
//dula=0;
while(1)
{//dula=0;
matrixkeyscan();
}
}
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