PC机与多台单片机串行通信介绍.pdfVIP

毕业设计（ 论 文 ）说明书 目 录 摘 要„„„„„„„„„„„„„„„„„„„„„„„„„„„„„„„Ⅱ Abstract „„„„„„„„„„„„„„„„„„„„„„„„„„„„„Ⅲ 第一章 绪论 „„„„„„„„„„„„„„„„„„„„„„„„„„„1 第二章 课题实施方案 „„„„„„„„„„„„„„„„„„„„„„„2 2.1 系统硬件设计 …………………………………………………………………2 2.2 系统软件设计 …………………………………………………………………3 第三章 硬件电路设计 „„„„„„„„„„„„„„„„„„„„„„„5 3.1 80C51 单片机结构及其串行通信原理 „„„„„„„„„„„„„„„5 3.2 串行接口及其差分转换电路 „„„„„„„„„„„„„„„„„„17 3.3 Protel DXP 2004 原理图设计„„„„„„„„„„„„„„„„„„20 第四章 系统软件设计 „„„„„„„„„„„„„„„„„„„„„„29 4.1 系统的通信协议 „„„„„„„„„„„„„„„„„„„„„„„29 4.2 C51 编程实现PC 机与单片机之间的串行通信 „„„„„„„„„„„29 4.3 Windows 集成开发环境uVision2 „„„„„„„„„„„„„„„„33 第五章 总结 „„„„„„„„„„„„„„„„„„„„„„„„„„39 致谢 „„„„„„„„„„„„„„„„„„„„„„„„„„„„„„41 参考文献 „„„„„„„„„„„„„„„„„„„„„„„„„„„„42 1 摘 要 本文详细介绍了基于RS-485 总线的PC 机与多台单片机间的串行通信原理、实现 方法和相应的通信硬件、软件设计。该设计是由PC 机与单片机组成的主从控制 系统，其中PC 机做为上位机对下位单片机是实现控制和监视功能。它包括通信 和控制两个功能模块。单片机作为下位机在整个系统中属于从属地位，主要用来 接收上位机的命令。由于此通信的PC 接口是RS232 的9 针接口，且下位机数目 有限（32 台）。所以本设计采用了RS485 总线以及RS232 转RS485 的协议芯片以 满足长距离多机通信，本文讨论了总线接口转换、主从式通信协议设计方法，给 出了采用中断式处理的通信过程流程图，并叙述了设计过程中必备的绘图软件 Protel DXP 的应用，以及编辑源代码软件keil uVision2 的应用，实现了PC 机对多 个单片机组成采集终端的通信与管理。 关键词： PC 机；单片机；RS485；通信 Abstract The communication 、realized method and corresponding design of hardware and software between PC and multiple MCUs based on RS-485 is described in detai in the article. This design instroduces a pincipal and subordinate control system which is composed of PC and single chip. Divided from its function, it includes tw parts: communication and control, in which PC is used as master, and MCUs is used as slave s as t receive the single order from the master.The bus interface conversion and the design of master-slave communication protocol is introduced and The program flowchart of communication with interrupt process is als given. In the process