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#include<reg52.h>
#define uint unsigned int
#define uchar unsigned char
uchar table[]={
0xc0,0xf9,0xa4,0xb0,
0x99,0x92,0x82,0xf8,
0x80,0x90,0x88,0x83,
0xc6,0xa1,0x86,0x8e
};
uint num;
uchar temp;
sbit duan=P1^0;
void delay(uint z)
{
uint i,j;
for(i=z;i>0;i--)
for(j=20;j>0;j--);
}
void display()
{
duan=1;
P0=table[num];
duan=0;
delay(50);
}
uchar keyboard(void)
{
P2=0xf0;
temp=P2;
P2=0x0f;
temp|=P2;
if(temp!=0xff)
{
P2=0xf0;
temp=P2;
P2=0x0f;
temp|=P2;
switch(temp)
{
case 0x7e:num=0;break;
case 0xbe:num=1;break;
case 0xde:num=2;break;
case 0xee:num=3;break;
case 0x7d:num=4;break;
case 0xbd:num=5;break;
case 0xdd:num=6;break;
case 0xed:num=7;break;
case 0x7b:num=8;break;
case 0xbb:num=9;break;
case 0xdb:num=10;break;
case 0xeb:num=11;break;
case 0x77:num=12;break;
case 0xb7:num=13;break;
case 0xd7:num=14;break;
case 0xe7:num=15;break;
}
while(temp!=0xff)
{
P2=0xf0;
temp=P2;
P2=0x0f;
temp|=P2;
}
display();
}
}
void main()
{
while(1)
{
keyboard();
}
}
這種方法比前一種方法簡(jiǎn)潔,同樣也更具有技巧性!
解釋?zhuān)?br />
當(dāng)P2=0xf0時(shí),temp的值為0x70,b0,d0,e0
當(dāng)P2=0x0f時(shí),temp'的值為0x0e,0d,0b,0e
則temp|=temp'的值為0x7e,0xbe,0xde,0xee
0x7d,0xbd,0xdd,0xed
0x7b,0xbb,0xdb,0xeb
0x77,0xb7,0xd7,0xe7
注意:我用的數(shù)碼管是共陽(yáng)極的,另外鍵盤(pán)的接法不同,鍵所對(duì)應(yīng)的位置也不一樣,如需使用,適當(dāng)更改即可!
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