}
P3=0x0f;//0000 1111
if(P3!=0x0f)
delayms(5);
if(P3!=0x0f){
switch(P3){
case 0x0e:keyboard=keyboard;break;//0000 1110 //行檢測
case 0x0d:keyboard=keyboard+4;break;//0000 1101
case 0x0b:keyboard=keyboard+8;break;//0000 1011
case 0x07:keyboard=keyboard+12;break;//0000 0111