目录
前言 ................................................................................5
1.1 研究背景及意义...........................................................................................................................5
1.2 国内外研究现状...........................................................................................................................6
1.3 课题的主要内容..........................................................................................................................7
1.4 论文的总体结构...........................................................................................................................8
2 设计任务及要求 .....................................................................8
2.1 方案设计与论证...........................................................................................................................8
2.2 主控单片机 AT89C51 单片机.....................................................................................................10
2.2.1 AT89C51 简 介 ................................................................................................................10
2.2.2 引脚说明 ............................................................................................................................10
2.2.3 AT89C51 接口设计 ............................................................................................................11
2.3 显示模块.....................................................................................................................................11
2.3 数码显示输出部分 ................................................................................................................11
2.4 三端可调稳压器.........................................................................................................................12
2.5 运算放大器 lm358......................................................................................................................13
2.5.2 应用简介 ............................................................................................................................13
2.6 数模转换芯片.............................................................................................................................14
3. 系统电路原理及硬件实现 ..........................................................15
3.1 系统总体框图.............................................................................................................................15
3.2 系统模块电路设计....................................................................................................................15
3.2.1 单片机控制模块 ...............................................................................................................15
3.2.2 稳压输出模块（lm317） .................................................................................................16
3.2.3 数模转换部分 ...................................................................................................................17
3.2.4 显示模块 ...........................................................................................................................18
3.2.5 电源模块 ............................................................................................................................19
3.3 键盘模块....................................................................................................................................19
3.3.1 系统整体原理图 ................................................................................................................20
4.系统的软件设计 ...................................................................20
4.1 件设计思路................................................................................................................................20
4.2 系统软件流程............................................................................................................................20
5.系统测试与误差分析 ...............................................................21
5.1 系统测试.....................................................................................................................................21
5.1.1 软件测试 ............................................................................................................................21
5.1.2 硬 件 测 试 .....................................................................................................................22
5.1.3 系统整体测试 ..................................................................................................................22
6 单片机系统抗干扰说明 .............................................................23
总结 ...............................................................................26
致谢 ...............................................................................27
参考文献 ...........................................................................28
