张家界航空工业职业技术学院毕业设计说明书目录摘要................................................................................................................................3引言................................................................................................................................4第一章课题分析与方案论证......................................................................................51.1选题的意义及目的.......................................................................................51.1.1方案论证..............................................................................................61.1.2方案一：感应考勤机..........................................................................61.1.4方案三：条码卡、磁卡、接触式IC卡............................................71.1.5方案比较.................................................................................................81.2课题要求................................................................................................8第2章硬件电路的设计..............................................................................................92.1AT89S52单片机简介...................................................................................92.1.1总述......................................................................................................92.2时钟模块的设计..........................................................................................102.2.1DS1302介绍.....................................................................................102.2.2时钟模块电路的硬件设计.......................................................................132.3K4模块的设计...........................................................................................132.3.1K4模块的介绍..................................................................................132.3.2K4模块的硬件电路设计.........................................................................152.4显示模块的设计..........................................................................................162.4.1LED的介绍.................