06-矩阵键盘

#include "reg52.h"

sfr P4 = 0xc0;

sbit R1 = P3^0;
sbit R2 = P3^1;
sbit R3 = P3^2;
sbit R4 = P3^3;

sbit C4 = P3^4;
sbit C3 = P3^5;
sbit C2 = P4^2;
sbit C1 = P4^4;

unsigned char code table[] = 
{
	0xc0,//0
	0xf9,//1
	0xa4,//2
	0xb0,//3
	0x99,//4
	0x92,//5
	0x82,//6
	0xf8,//7
	0x80,//8
	0x90,//9
	0x88,//A
	0x83,//B
	0xc6,//C
	0xa1,//D
	0x86,//E
	0x8e,//F
	0xbf,//-
	0x7f//.
};

void HC138(unsigned char n)
{
	switch(n)
	{
		case 4:
			P2 = (P2&0x1f) | 0x80;
		break;
		case 5:
			P2 = (P2&0x1f) | 0xa0;
		break;
		case 6:
			P2 = (P2&0x1f) | 0xc0;
		break;
		case 7:
			P2 = (P2&0x1f) | 0xe0;
		break;
		
	}
}

void display(unsigned char val)
{
	HC138(6);
	P0 = 0x01;
	HC138(7);
	P0 = table[val];
	
}

unsigned char key_num = 0;
void scan()
{
	R1 = 0;
	R2 = 1;
	R3 = 1;
	R4 = 1;
	
	C1 = 1;
	C2 = 1;
	C3 = 1;
	C4 = 1;
	if(C1 == 0)
	{
		while(C1 == 0);
		key_num = 0;
		display(key_num);
	}
	else if(C2 == 0)
	{
		while(C2 == 0);
		key_num = 1;
		display(key_num);
	}
	else if(C3 == 0)
	{
		while(C3 == 0);
		key_num = 2;
		display(key_num);
	}
	else if(C4 == 0)
	{
		while(C4 == 0);
		key_num = 3;
		display(key_num);
	}
	
	R1 = 1;
	R2 = 0;
	R3 = 1;
	R4 = 1;
	
	C1 = 1;
	C2 = 1;
	C3 = 1;
	C4 = 1;
	if(C1 == 0)
	{
		while(C1 == 0);
		key_num = 4;
		display(key_num);
	}
	else if(C2 == 0)
	{
		while(C2 == 0);
		key_num = 5;
		display(key_num);
	}
	else if(C3 == 0)
	{
		while(C3 == 0);
		key_num = 6;
		display(key_num);
	}
	else if(C4 == 0)
	{
		while(C4 == 0);
		key_num = 7;
		display(key_num);
	}
	
	R1 = 1;
	R2 = 1;
	R3 = 0;
	R4 = 1;
	
	C1 = 1;
	C2 = 1;
	C3 = 1;
	C4 = 1;
	if(C1 == 0)
	{
		while(C1 == 0);
		key_num = 8;
		display(key_num);
	}
	else if(C2 == 0)
	{
		while(C2 == 0);
		key_num = 9;
		display(key_num);
	}
	else if(C3 == 0)
	{
		while(C3 == 0);
		key_num = 10;
		display(key_num);
	}
	else if(C4 == 0)
	{
		while(C4 == 0);
		key_num = 11;
		display(key_num);
	}
	
	R1 = 1;
	R2 = 1;
	R3 = 1;
	R4 = 0;
	
	C1 = 1;
	C2 = 1;
	C3 = 1;
	C4 = 1;
	if(C1 == 0)
	{
		while(C1 == 0);
		key_num = 12;
		display(key_num);
	}
	else if(C2 == 0)
	{
		while(C2 == 0);
		key_num = 13;
		display(key_num);
	}
	else if(C3 == 0)
	{
		while(C3 == 0);
		key_num = 14;
		display(key_num);
	}
	else if(C4 == 0)
	{
		while(C4 == 0);
		key_num = 15;
		display(key_num);
	}
}

void main()
{
	while(1)
	{
		scan();
	}
}