key_test.c

单片机实现按键的功能程序

#include<reg51.h>
#include"key_test.h"

void delay()
{	uchar i,j;
	for(i=0;i<50;i++)
	for(j=0;j<255;j++);
}
char keypad_scan()
{
	char key,i;
	keyout=0xf0;
	while(keyout!=0xf0);
	do{
		for(i=0;i<=3;i++)
		{
			keyout=ksp[i];
			if(keyout!=ksp[i])
			{
				delay();
				key=keyout;
				if(key!=ksp[i]) 
					return(key);
			}		
		}
	}while(1);
}
char gotkey()
{
	char temp,i;
	temp=keypad_scan();
	for(i=0;i<=15;i++)
	{
		if(temp==key_code[i])	return(i);
	}
	 return(16);	
} 

void main()
{	
while(1)
{
	P2=0xaa;
	delay();
	P2=0x55;
 }
}