矩阵键盘扫描程序.c

单片机的矩阵键盘扫描程序

#include <reg52.h>
#include "define.h"
uint temp,n,num;
uchar code smgtable[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71,0};
void display(uchar);
void delay(uint ms);
uchar keyscan();
void main()
{   
    num=17;
    LEDLK=0;
	while(1)
	{
        n=keyscan();
        display(n);
        delay(5);  
     }
}
void display(uchar num1)
{
	SMGLK=1;
	P2=0xf0;;
	SMGLK=0;
	SMGBITLK=1;
	P2=smgtable[num1-1];
	SMGBITLK=0;
}
void delay(uint ms)
{
	uint x,y;
	for(x=0;x<ms;x++)
		for(y=0;y<120;y++)
				;
}
uchar keyscan()
{
        P3=0xfe;
        temp=P3;
        temp=temp&0xf0;
        while(temp!=0xf0)
            {
                delay(5);
                temp=P3;
                temp=temp&0xf0;
                while(temp!=0xf0)
                    {
                        temp=P3;
                        switch(temp)
                        {
                            case 0xee: num=1;
                            break;
                            case 0xde: num=2;
                            break;
                            case 0xbe: num=3;
                            break;
                            case 0x7e: num=4;
                            break;
                        }
                        while(temp!=0xf0)
                        {
                            temp=P3;
                            temp=temp&0xf0;
                        }
                    }           
             }
        P3=0xfd;
        temp=P3;
        temp=temp&0xf0;
        while(temp!=0xf0)
            {
                delay(5);
                temp=P3;
                temp=temp&0xf0;
                while(temp!=0xf0)
                    {
                        temp=P3;
                        switch(temp)
                        {
                            case 0xed: num=5;
                            break;
                            case 0xdd: num=6;
                            break;
                            case 0xbd: num=7;
                            break;
                            case 0x7d: num=8;
                            break;
                        }
                        while(temp!=0xf0)
                        {
                            temp=P3;
                            temp=temp&0xf0;
                        }
                    }           
             }
        P3=0xfb;
        temp=P3;
        temp=temp&0xf0;
        while(temp!=0xf0)
            {
                delay(5);
                temp=P3;
                temp=temp&0xf0;
                while(temp!=0xf0)
                    {
                        temp=P3;
                        switch(temp)
                        {
                            case 0xeb: num=9;
                            break;
                            case 0xdb: num=10;
                            break;
                            case 0xbb: num=11;
                            break;
                            case 0x7b: num=12;
                            break;
                        }
                        while(temp!=0xf0)
                        {
                            temp=P3;
                            temp=temp&0xf0;
                        }
                    }           
             }
        P3=0xf7;
        temp=P3;
        temp=temp&0xf0;
        while(temp!=0xf0)
            {
                delay(5);
                temp=P3;
                temp=temp&0xf0;
                while(temp!=0xf0)
                    {
                        temp=P3;
                        switch(temp)
                        {
                            case 0xe7: num=13;
                            break;
                            case 0xd7: num=14;
                            break;
                            case 0xb7: num=15;
                            break;
                            case 0x77: num=16;
                            break;
                        }
                        while(temp!=0xf0)
                        {
                            temp=P3;
                            temp=temp&0xf0;
                        }
                    }           
             }
    return num;
}