keyboard.h

来自「单片机C51控制」· C头文件 代码 · 共 27 行

void dlms(void)
{
	unsigned char i;
	for(i=200;i>0;i--)
	{}
}

unsigned char keyboard()
{
	unsigned char scode1,scode2,recode;
	P1=0xf0;
    dlms();
	if((P1&0xf0)!=0xf0)
		{
			dlms();
			if((P1&0xf0)!=0xf0)
				{   
					scode1=P1;
					P1=0x0f;
                    dlms();
					scode2=P1;
					recode=(scode1|scode2);
					return(recode);						
				}
		}
		return(0);
}