keyboard.c

在keil下实现的普通4X4键盘和595显示驱动

#include<reg51.h>
#include<intrins.h>

#define uchar unsigned char
#define port P1
uchar code encode[]={0xc0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0xff};//0~9

uchar keyvalue,ledbuff4[4];
uchar cnter4;
bit keyflag;

void delay500(uchar n)
{
    uchar i;
    for( ; --n ; )
	for( i=80 ; i!=0 ; --i );
}

void keyscan()
{
    uchar a,b,c;
    keyflag = 0;
    port = 0xff;
    port = 0x0f;
    if( port==0x0f ) return;
    delay500( 20 );
    if( port==0x0f ) return ;
    keyflag = 1;
    a = port;
    port = 0xf0;
    _nop_();
    b = port;
    c = a^b;
    switch( c )
    {
        case 0x77: keyvalue=0; break;   //对按键附值//
        case 0x7b: keyvalue=1; break;  
        case 0x7d: keyvalue=2; break;  
        case 0x7e: keyvalue=3; break;  
        case 0xb7: keyvalue=4; break;  
        case 0xbb: keyvalue=5; break;  
        case 0xbd: keyvalue=6; break;  
        case 0xbe: keyvalue=7; break;  
        case 0xd7: keyvalue=8; break;  
        case 0xdb: keyvalue=9; break;  
        case 0xdd: keyvalue=10;break;  
        case 0xde: keyvalue=11;break;  
        case 0xe7: keyvalue=12;break;  
        case 0xeb: keyvalue=13;break;  
        case 0xed: keyvalue=14;break;  
        case 0xee: keyvalue=15;break;
    }
}

void display4()
{
    uchar t=cnter4;
	P2 = 0xff;
	_nop_() , _nop_() , _nop_();
	t = t%4;
	if( t==0 )
	    P2 = encode[ledbuff4[0]] , P0 = 0xf7;
	else if( t==1 )
	    P2 = encode[ledbuff4[1]] , P0 = 0xfb;
	else if( t==2 )
	    P2 = encode[ledbuff4[2]] , P0 = 0xfd;
	else if( t==3 )
	    P2 = encode[ledbuff4[3]] , P0 = 0xfe;
	else
	    P2 = 0xfe , P0 = 0xf0;
}

void initbuff4()
{
    ledbuff4[3] = 10 , ledbuff4[2] = 10;
    ledbuff4[0] = keyvalue%10;
    if( keyvalue>=10 )
	    ledbuff4[1] = 1;
	else
	    ledbuff4[1] = 0x0a;
}

int main()
{
    SP = 0x60 , EA = 0;
    cnter4 = 0;
	TH0 = (65536-400)/256;
	TL0 = (65536-400)%256;
	TMOD = 0x01 , TCON = 0x10;
	IE = 0x82;
    while( 1 )
    {
        keyscan();
        initbuff4();
        delay500(200);
    }
}

void t0isr()using 2 interrupt 1
{
	TR0 = 1;
    TH0 = (65536-2500)/256;
	TL0 = (65536-2500)%256;
	cnter4 = (cnter4+1)&0x03;//0~128
	display4();
}