本程序可改进的地方：按键状态机中，将等待按键释放语句移到第三个状态中，可进一步提高按键扫描程序效率。

#include

#defineucharunsignedchar

#defineuintunsignedint

sbitdula=P3^0;

sbitwela=P3^1;

#definekeyport(P1)

#definekeystate00//按键确认状态

#definekeystate11//按键无动作状态

charkeystate=1;//按键状态初始化为按键无动作状态

ucharkeynum=0;

voiddelayms(uintx)//1ms

{

uinty,z;

for(y=x;y>0;y--)

for(z=111;z>0;z--);

}

ucharcodetable[]={//共阳数码管

0xc0,0xf9,0xa4,0xb0,

0x99,0x92,0x82,0xf8,

0x80,0x90,0x88,0x83,

0xc6,0xa1,0x86,0x8e};

voidsmg()

{

dula=0;

wela=0;

P2=0x01;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x02;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x04;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x08;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x10;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x20;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x40;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

P2=0x80;

wela=1;

wela=0;

P2=table[keynum];

dula=1;

dula=0;

delayms(1);

}

voidkeyscan()

{

uchartemp1,temp2,column,row;

switch(keystate)

{

casekeystate0://keystate0，按键按下确认状态，下一状态为keystate1(按键无动作状态)

keyport=0x0f;

temp1=keyport;

keyport=0xf0;

temp2=keyport;

if((temp1|temp2)!=0xff)

{

temp1|=temp2;

if(!(temp1&0x80))

row=3;

else

if(!(temp1&0x40))

row=2;

else

if(!(temp1&0x20))

row=1;

else

if(!(temp1&0x10))

row=0;

if(!(temp1&0x08))

column=3;

else

if(!(temp1&0x04))

column=2;

else

if(!(temp1&0x02))

column=1;

else

if(!(temp1&0x01))

column=0;

keynum=column*4+row;

while(!(keyport==0x0f|keyport==0xf0));

keystate=keystate1;

break;

}

else

keystate=keystate1;

break;

casekeystate1://keystate1，按键无动作状态，下一状态为keystate0(按键无动作状态)

keyport=0x0f;

temp1=keyport;

keyport=0xf0;

temp2=keyport;

if((temp1|temp2)!=0xff)

{

keystate=keystate0;

}

else

keystate=keystate1;

break;

}

}

voidmain()

{

while(1)

{

keyscan();

smg();

}

}