AVR单片机(ATMEGA16)矩阵键盘扫描程序

程序思路与缺陷参考：51单片机(AT89C52)矩阵键盘检测程序

#include

typedef unsigned char uchar;

typedef unsigned int uint;

#define dula_h PORTD|=0x01

#define dula_l PORTD&=0xfe

#define wela_h PORTD|=0x02

#define wela_l PORTD&=0xfd

#define keyport PORTB

#define keypin (PINB)

#define keydre DDRB

#define keystate0 0 //按键确认状态

#define keystate1 1 //按键无动作状态

char keystate=1; //按键状态初始化为按键无动作状态

uchar keynum=0;

void delayms(uint z) //1ms

{

uint x,y;

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

for(y=157;y>0;y--);

}

uchar table[]={ //共阳数码管

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

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

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

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

void smg(void)

{

dula_l;

wela_l;

PORTC=0x01;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x02;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x04;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x08;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x10;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x20;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x40;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

PORTC=0x80;

wela_h;

wela_l;

PORTC=table[keynum];

dula_h;

dula_l;

delayms(1);

}

void keyscan(void)

{

uchar temp1,temp2,column,row;

switch(keystate)

{

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

keydre=0xff;

keyport=0x0f;

keydre=0xf0;

temp1=keypin;

keydre=0xff;

keyport=0xf0;

keydre=0x0f;

temp2=keypin;

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;

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

keydre=0xff;

keyport=0x0f; //输出0x0f

keydre=0xf0;

temp1=keypin;

keydre=0xff;

keyport=0xf0; //输出0xf0

keydre=0x0f;

temp2=keypin;

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

{

keystate=keystate0;

}

else

keystate=keystate1;

break;

}

}

void main(void)

{

DDRC=0xff;

DDRD|=0x03;

while(1)

{

keyscan();

smg();

}

}