独立按键基操和扩展应用

基本操作

#include<reg52.h>

sbit S7 = P3^0;
sbit S6 = P3^1;
sbit S5 = P3^2;
sbit S4 = P3^3;

sbit L1 = P0^0;
sbit L2 = P0^1;
sbit L3 = P0^2;
sbit L4 = P0^3;
sbit L5 = P0^4;
sbit L6 = P0^5; 

 void SelectHC573(unsigned char n)
{ 
 switch(n)
 {
  case 4:P2=(P2 & 0x1f) | 0x80;	 break;
  case 5:P2=(P2 & 0x1f) | 0xa0;	 break;
  case 6:P2=(P2 & 0x1f) | 0xc0;	 break;
  case 7:P2=(P2 & 0x1f) | 0xe0;	 break;
 }
}

void Delay(unsigned char t)
{
 while(t--);
}

void ScanKeys_Alone()
{
if(S7==0)
{
 Delay(100);
 if(S7==0)
 {
  L1=0;
  while(S7==0);
  L1=1;
 }
}

if(S6==0)
{
 Delay(100);
 if(S6==0)
 {
  L2=0;
  while(S6==0);
  L2=1;
 }
}

 if(S5==0)
{
 Delay(100);
 if(S5==0)
 {
  L3=0;
  while(S5==0);
  L3=1;
 }
}


 if(S4==0)
{
 Delay(100);
 if(S4==0)
 {
  L4=0;
  while(S4==0);
  L4=1;
 }
}

}


void main()
{
SelectHC573(4);
while(1)
{
 ScanKeys_Alone();
}
}