目  录

1 绪论................................................................................................1

1.1发展概况与设计背景............................................................1

1.2本设计概述........................................................................2

2总体设计方案........................................................... ................3

2.1方案选择论证....................................................... .............3

2.2主控芯片单片机的选择....................................... .............3

2.2.1 AT89C51的主要性能.................................................4

2.2.2 AT89C51的引脚结构.................................................5

2.3传感器的选择..........................................................................6

 2.3.1传感器的红外辐射与红外探测的原理结构................7

2.3.2红外测温原理....................................................................7

2.3.3热释红外传感器的结构.................................................8

2.3.4 菲涅尔透镜..................................................................10

2.4热释电红外传感器控制电路芯片的选择..........................11

3 系统硬件设计.......................................................................….13

3.1低频带通放大电路..............................................................13

3.2电压比较整形电路..............................................................14

3.2.1双限电压比较器的工作原理.......................................14

3.3报警电路..............................................................................15

3.4灯光警示电路......................................................................16

3.5状态显示电路......................................................................17

3.6供电电源电路......................................................................17

3.7单片机最小系统..................................................................18

4 系统软件....................................................................................19

  4.1主程序流程图......................................................................19

  4.2中断函数流程图..................................................................20

5结论.............................................................................................21

致谢................................................................................................22

参考文献..............................................................................................23

附录一：系统电路图....................................................................24

附录二：系统程序........................................................................25