江汉大学文理学院毕业设计说明书
目录
摘要.......................................................................................................................5
abstract...................................................................................................................6
1.引言.....................................................................................................................7
1 绪论.....................................................................................................................8
1.1 本设计在国内外的研究现状...................................................................8
1.2 本设计的选题及意义...............................................................................9
1.3 国内外电子称发展及成果.....................................................................12
2 整体方案设计...................................................................................................14
2.1 设计任务.................................................................................................14
2.2 设计要求.................................................................................................14
2.3 方案选择.................................................................................................15
2.3.2 方案一...........................................................................................15
2.3.3 方案二...........................................................................................16
3 硬件电路的设计...............................................................................................18
3.1 传感器电路设计.....................................................................................18
3.2 放大电路及 A/D 转换电路设计............................................................21
3.2.1 HX711 芯片介绍..........................................................................21
3.2.2 HX711 特点..................................................................................22
3.2.3 HX711 引脚功能..........................................................................23
3.2.4 HX711 管脚说明..........................................................................24
3.2.5 信号放大电路...............................................................................27
3.2.6 A/D 转换电路...............................................................................28
3.2.7 A/D 转换器的主要性能指标.......................................................30
3.3 控制单片机的选型.................................................................................31
3.3.1 AT89C51 引脚功能......................................................................33
3.3.2 晶振电路.......................................................................................38
3.3.3 复位电路.......................................................................................39
3.4 键盘电路.................................................................................................40
3.5 显示系统电路的设计.............................................................................42
3.5.1 显示方式选择...............................................................................42
3.5.2 LCD LM016L 的结构及引脚功能...............................................42
3.5.3 显示电路的硬件设计...................................................................43
3.6 报警电路的设计.....................................................................................44
结 论.....................................................................................................................46
参考文献..............................................................................................................47
致 谢.....................................................................................................................48
