keyscanf.h

单片机控制电子门 密码锁

uchar keyscanf(void)
{
	uchar temp,key1,key2;
	P1 = 0xf0;			 					// 发全0行扫描码
	if ((P1&0xf0)!=0xf0)					// 若有键按下
	{
		delay(15);							// 去抖动
		if ((P1&0xf0)!=0xf0)				// 延时后再判断一次，去除抖动影响
		{
			temp=0xfe;
			while((tmp&0x10)!=0)		// 逐行扫描
			{
				P1 = temp;				// 输出行扫描码
				if ((P1&0xf0)!=0xf0)		// 本行有键按下
				{
					LED=~LED;
					key1 = (P1&0xf0)|0x0f;
					while((P1&0xf0)!=0xf0);
					key2=(~temp)+(~key1);
					switch(key2)
   					{
			      		case 0x28:return 0; break;//0
						case 0x11:return 1;	break;			
						case 0x21:return 2;	break;
			     		case 0x41:return 3;	break;
						case 0x12:return 4;	break;
						case 0x22:return 5;	break;
						case 0x42:return 6;	break;
						case 0x14:return 7;	break;
						case 0x24:return 8;	break;
						case 0x44:return 9;	break;//9
						case 0x48:return 10;break;//#
						case 0x18:return 11;break;//*	
						default:break;
					}
				}
				else
				temp = (temp<<1)|0x01;		// 行扫描码左移一位
			}
		}
	}
	return 255;								// 无键按下，返回值为20 	
}