Keil51单片机数码管鬼影显示问题

Keil51单片机数码管鬼影显示问题

所为的鬼影就是程序逻辑正确，但电路逻辑有问题。就是按程序逻辑，前一个数字显示后，直接显示下一组数字，因为没清干净，导致瞬间残留；

处理的办法，就是有就显示，没有就让数码管处于关闭状态。

while(1)
{

if (cnt >= 100)
{

cnt = 0; //time length control
Sec++; //1x1000ms=1 second

switch (j)
{

case 0:
{

if (Sec>9)
{
j++;

}
else
{
LedBuff[0] = LedChar[Sec%10];  //正常显示
LedBuff[1] = 0xFF;   //关闭显示
LedBuff[2] = 0xFF;   //关闭显示
LedBuff[3] = 0xFF;   //关闭显示
LedBuff[4] = 0xFF;    //关闭显示
LedBuff[5] = 0xFF;     //关闭显示
};
};break;

case 1:
{

if (Sec>99)
{
j++;
}
else
{
LedBuff[0] = LedChar[Sec%10];
LedBuff[1] = LedChar[Sec/10%10];
LedBuff[2] = 0xFF;
LedBuff[3] = 0xFF;
LedBuff[4] = 0xFF;
LedBuff[5] = 0xFF;
};
};break;

case 2:
{

if (Sec>999)
{
j++;
}
else
{
LedBuff[0] = LedChar[Sec%10];
LedBuff[1] = LedChar[Sec/10%10];
LedBuff[2] = LedChar[Sec/100%10];
LedBuff[3] = 0xFF;
LedBuff[4] = 0xFF;
LedBuff[5] = 0xFF;
};
};break;

case 3:
{

if (Sec>9999)
{
j++;
}
else
{
LedBuff[0] = LedChar[Sec%10];
LedBuff[1] = LedChar[Sec/10%10];
LedBuff[2] = LedChar[Sec/100%10];
LedBuff[3] = LedChar[Sec/1000%10];
LedBuff[4] = 0xFF;
LedBuff[5] = 0xFF;
};
};break;

case 4:
{

if (Sec>99999)
{
j++;
}
else
{
LedBuff[0] = LedChar[Sec%10];
LedBuff[1] = LedChar[Sec/10%10];
LedBuff[2] = LedChar[Sec/100%10];
LedBuff[3] = LedChar[Sec/1000%10];
LedBuff[4] = LedChar[Sec/10000%10];
LedBuff[5] = 0xFF;
};
};break;

case 5:
{

if (Sec>999999)
{
j=0;
Sec = 0;
}
else
{
LedBuff[0] = LedChar[Sec%10];
LedBuff[1] = LedChar[Sec/10%10];
LedBuff[2] = LedChar[Sec/100%10];
LedBuff[3] = LedChar[Sec/1000%10];
LedBuff[4] = LedChar[Sec/10000%10];
LedBuff[5] = LedChar[Sec/100000%10];
};
};break;
default: break;

};

};

};