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void Keys_Scan()
{
uchar Tmp;
P1 = 0x0f;
DelayMS(1);
Tmp = P1 ^ 0x0f;
switch(Tmp)
{
case 1: KeyNO = 0; break;
case 2: KeyNO = 1; break;
case 4: KeyNO = 2; break;
case 8: KeyNO = 3; break;
default: KeyNO = 16;
}
P1 = 0xf0;
DelayMS(1);
Tmp = P1 >> 4 ^ 0x0f;
switch(Tmp)
{
case 1: KeyNO += 0; break;
case 2: KeyNO += 4; break;
case 4: KeyNO += 8; break;
case 8: KeyNO += 12;
}
}
里面的 P1 = 0x0f;
DelayMS(1);
Tmp = P1 ^ 0x0f; |
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