key.c

打印机控制程序

#include "config.h"
#include <REGX52.H>

sbit BUTTON1 = P1^0;
sbit BUTTON2 = P1^1;
sbit BUTTON3 = P1^2;
sbit BUTTON4 = P1^3;

delay1()
{
	unsigned int delay1;
	for(delay1=0;delay1<30000;delay1++);
}


unsigned char wait_key()
{
	while(1)
	{
		if(BUTTON1==0)
		{
			delay1();
			if(BUTTON1==0)
			{
				return(KEY1);
			}
		}
		else if(BUTTON2==0)
		{
			delay1();
			if(BUTTON2==0)
			{
				return(KEY2);
			}
		}
		else if(BUTTON3==0)
		{
			delay1();
			if(BUTTON3==0)
			{
				return(KEY3);
			}
		}
		else if(BUTTON4==0)
		{
			delay1();
			if(BUTTON4==0)
			{
				return(KEY4);
			}
		}
	}	
}