原理
实现
矩阵键盘点亮静态数码管
#include "reg52.h"
#include "intrins.h"
typedef unsigned char u8;
typedef unsigned int u16;
#define GPIO_DIG P0
#define GPIO_KEY P1
u8 code smgduan[16]={
//0123456789abcdef
0x3f,0x06,
0x5b,0x4f,
0x66,0x6d,
0x7d,0x07,
0x7f,0x6f,
0x77,0x7c,
0x39,0x5e,
0x79,0x71
};//共阴
u8 KeyValue;
void delay(u16 i)
{
while(i--);
}
//行列扫描
void KeyDown()
{
char a=0;
GPIO_KEY=0x0f;//高4位低电平,低4位高电平
if(GPIO_KEY!=0x0f)
{
delay(1000);
if(GPIO_KEY!=0x0f)
{
//判断哪一列按下
switch(GPIO_KEY)
{
case(0x07):KeyValue=0;break;
case(0x0b):KeyValue=1;break;
case(0x0d):KeyValue=2;break;
case(0x0e):KeyValue=3;break;
}
GPIO_KEY=0xf0;
switch(GPIO_KEY)
{
case(0x70):KeyValue=KeyValue;break;
case(0xb0):KeyValue=KeyValue+4;break;
case(0xd0):KeyValue=KeyValue+8;break;
case(0xe0):KeyValue=KeyValue+12;break;
}
while((a<50)&&(GPIO_KEY!=0xf0))
{
delay(100);
a++;
}
}
}
}
void main()
{
while(1)
{
KeyDown();
GPIO_DIG=~smgduan[KeyValue];
}
}