使用4*4的矩阵键盘和一个数码管
在4*4的矩阵键盘上编码0-F的字符，和一个数码管显示每个键盘上输入的字符。
//4*4键盘检测程序,按下键后相应的代码显示在数码管上
#include
typedef unsigned char UINT8;
UINT8 i=100;
UINT8 j,k,temp,key;
void delay(unsigned char i)
{
for(j=i;j>0;j--)
for(k=125;k>0;k--);
}
UINT8 code table[]=
{
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71
};
void display(unsigned char num)
{
P0=table[num];
}
void init_led()
{
P0 = 0x00;
}
void main()
{
while(1)
{
P1 = 0xef;
temp = P1;
temp = temp&0xf0;
if (temp != 0xf0)
{
temp = P1;
switch(temp)
{
case 0xee:
key=0;
break;
case 0xed:
key=1;
break;
case 0xeb:
key=2;
break;
case 0xe7:
key=3;
break;
default:
break;
}
display(key);
P1=0xfe;
}
P1 = 0xdf;
temp = P1;
temp = temp&0x0f;
if(temp != 0x0f)
{
temp = P1;
switch(temp)
{
case 0xde:
key = 4;
break;
case 0xdd:
key = 5;
break;
case 0xdb:
key = 6;
break;
case 0xd7:
key = 7;
break;
default:
break;
}
display(key);
}
P1=0xbf;
temp=P1;
temp=temp&0x0f;
if(temp != 0x0f)
{
temp=P1;
switch(temp)
{
case 0xbe:
key=8;
break;
case 0xbd:
key=9;
break;
case 0xbb:
key=10;
break;
case 0xb7:
key=11;
break;
default:
break;
}
display(key);
}
P1=0x7f;
temp=P1;
temp=temp&0x0f;
if(temp!=0x0f)
{
temp=P1;
switch(temp)
{
case 0x7e:
key=12;
break;
case 0x7d:
key=13;
break;
case 0x7b:
key=14;
break;
case 0x77:
key=15;
break;
default:
break;
}
display(key);
}
}
}
这个上面有一个bug就是每进入的时候数码管不是空的而是现实“0”这个没有解决。
