矩阵按键

电路图：


代码：

#include <REG52.h>

unsigned char code table[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

sbit h1=P1^0;
sbit h2=P1^1;
sbit h3=P1^2;
sbit h4=P1^3;
sbit l1=P1^4;
sbit l2=P1^5;
sbit l3=P1^6;
sbit l4=P1^7;

void delay(int num)
{
    int i,j;
    for(i=0;i<num;i++)
        for(j=0;j<150;j++)
            ;
}

unsigned char scanfcode()
{
    unsigned char table_h[]={0xfe, 0xfd, 0xfb, 0xf7};
    unsigned char i;
    for(i=0;i<4;i++)
    {
        P1=table_h[i];
        if(l1==0)
            return i*4+0;
        else if(l2==0)
            return i*4+1;
        else if(l3==0)
            return i*4+2;
        else if(l4==0)
            return i*4+3;
    }
}

int main()
{
    P2=0X02;
    while(1)
    {
        P1=0XF0;
        if(P1!=0XF0)
        {
            delay(20);
            if(P1!=0XF0)
            {
                P0=table[scanfcode()];
            }
        }
    }
}