key.c

来自「四线八拍步进电机驱动程序」· C语言 代码 · 共 37 行

#include<W78E365.h>
#include<util.h>
#include<key.h>

sbit addr_key=P2^0;

unsigned char keyscan(void)		//键盘扫描
{
	unsigned char keyval;
//	addr_key=1;
	P0=0xff;
	addr_key=0;
	if(P0==0xff)		
	{
		addr_key=1;
		return 0;
	}
	else
	{
	   	keyval=P0;
		delay(5000);  //delay,typically 10ms
//		addr_key=1;
		P0=0xff;
//		addr_key=0;
		if (P0==keyval)
		{	
			while(P0!=0xff);
			addr_key=1;
			return keyval;
		}
		else
		{
			addr_key=1;
			return 0;
		}
	 }
}