矩阵键盘及其数码管显示教程.doc

矩阵键盘及其数码管显示

电路图如上图所示。程序是用C语言编写的。程序如下：
#include<reg52.h>
#defineuintunsignedint
#defineucharunsignedchar
ucharcodetable[]={0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71,0x00};
sbitwela=P2^7;
sbitdula=P2^6;
ucharnum=17,temp;
voiddelay(uintz);
voidmain()
{
wela=1;
P1=0xc0;
wela=0;
dula=1;
P1=0x00;
dula=0;
while(1)
{
P3=0xfe;
temp=P3;
temp=temp&0xfe;
while(temp!=0xfe)
{
delay(5);
temp=P3;
switch(temp)
{
case0xee:num=1;break;
case0xde:num=2;break;
case0xbe:num=3;break;
case0x7e:num=4;break;
}
while(temp!=0xfe)
{
temp=P3;
temp=temp&0xfe;
}
dula=1;
P1=table[num-1];
dula=0;
}

P3=0xfd;
temp=P3;
temp=temp&0xfd;
while(temp!=0xfd)
{
delay(5);
temp=P3;
switch(temp)
{
case0xed:num=5;break;
case0xdd:num=6;break;
case0xbd:num=7;break;
case0x7d:num=8;break;
}
while(temp!=0xfd)
{
temp=P3;
temp=temp&0xfd;
}
dula=1;
P1=table[num-1];
dula=0;
}
P3=0xfb;
temp=P3;
temp=temp&0xfb;
while(temp!=0xfb)
{
delay(5);
temp=P3;
switch(temp)
{
case0xeb:num=9;break;
case0xdb:num=10;break;
case0xbb:num=11;break;
case0x7b:num=12;break;
}
while(temp!=0xfb)
{
temp=P3;
temp=temp&0xfb;
}
dula=1;
P1=table[num-1];
dula=0;
}
P3=0xf7;
temp=P3;
temp=temp&0xf7;
while(temp!=0xf7)
{
delay(5);
temp=P3;
switch(temp)
{
case0xe7:num=13;break;
case0xd7:num=14;break;
case0xb7:num=15;break;
case0x77:num=16;break;
}
while(temp!=0xf7)
{
temp=P3;
temp=temp&0xf7;
}
dula=1;
P1=table[num-1];
dula=0;
}
}
}

voiddelay(uintz)
{
uintx,y;
for(x=z;z>0;z--)
for(y=100;y>0;y--);
}