單片機掃描方式的鍵盤輸入實驗

電梯直達

樓主

ID:72519 發表于 2015-1-21 23:30 | 只看該作者回帖獎勵

是用51hei單片機開發板電路圖詳見：http://m.zg4o1577.cn/f/51hei-5.pdf 的數碼管部分，用2個74hc573 鎖存，p0口作為數據口，注意圖中要改一下p3.6和p3.7分別是段和位的鎖存端口.P2口上面是按鍵 p1口上面是8個led燈.

#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
uchar code DIS_SEG7[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
uchar code DIS_BIT[8]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
uchar code SKEY[16]={1,2,3,10,4,5,6,11,7,8,9,12,14,0,15,13};
uchar code act[4]={0xfe,0xfd,0xfb,0xf7};
sbit D=P3^6;
sbit V=P3^7;
//=======================
void delay(uint k)
{
uint data i,j;
for(i=0;i<k;i++){
for(j=0;j<121;j++)
{;}}
}
//==============
void delay10ms(void)
{
uint data i,j;
for(i=0;i<10;i++){
for(j=0;j<121;j++)
{;}}
}
//================
char scan_key(void)
{
uchar i,j,in,ini,inj;
bit find=0;
for(i=0;i<4;i++)
{
P1=act[i];
delay10ms();
in=P1;
in=in>>4;
in=in|0xf0;
for(j=0;j<4;j++)
{
if(act[j]==in)
{find=1;
inj=j;ini=i;
}
}
}
if(find==0)return-1;
return (ini*4+inj);
}
//============
void main(void)
{char c;
uchar key_value;
D=1;P0=0xff;D=0;V=1;P0=0xfe;V=0;
while(1)
{
delay(5000);
c=scan_key();
if(c!=-1)key_value=SKEY[c];
if(key_value==1){D=1;P0=0xff;D=0;V=1;P0=0xff;V=0;}
}
}