線反轉(zhuǎn)法:
#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
uchar num;
uchar codeSSEG[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
void delay1ms(uint z)
{
uint x;
uchar y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
void keyscan()
{
uchar temp,z;
P2=0xf0;
if(P2!=0xf0)
{
delay1ms(10);
if(P2!=0xf0)
{
temp=P2;
P2=0x0f;
z=temp|P2;
temp=P2&0x0f;
while(temp!=0x0f)//松手檢測(cè)
{
temp=P2&0x0f;
}
switch(z)
{
case0xee: num =0; break;
case 0xde: num =1; break;
case 0xbe: num =2; break;
case 0x7e: num =3; break;
case 0xed: num =4; break;
case 0xdd: num =5; break;
case 0xbd: num =6; break;
case 0x7d: num =7; break;
case 0xeb: num =8; break;
case 0xdb: num =9;break;
case 0xbb: num =10;break;
case 0x7b: num =11;break;
case 0xe7: num =12;break;
case 0xd7: num =13;break;
case 0xb7: num =14;break;
case 0x77: num =15;break;
}
}
}
}
void main()
{
num=0xff;
P2=0xff;
while(1)
{
keyscan();
P1=~SSEG[num];
}
}