【正文】 onitor System Based on CAN Bus Abstract The design of the AT89S51 microcontroller as the core principle of the temperature control system and design method to study the CAN bus data munication between control system, structural flexibility, universal also use a single bustype digital temperature sensor DS18B20, the system has a temperature measurement error is small, high resolution, antiinterference ability, dynamic show the way and so CAN bus used as a controller and 82C250 chip design of the CAN bus interface bus can provide differential transmit and receive functions, improve the system bus drive capability of nodes, increasing the munication distance and reduce interference. CAN bus full finishing the basic principles of temperature measurement systems, development history and describes the design method with the CANbusrelated, a description of the ponents used in the introduction, and a CAN bus node design circuit design, design clock circuit and reset final design of the CANbus temperature detection system software design and flow chart. Temperature detection both in the field of medical electronics field or industrial control applications are very wide, people need all kinds of furnace, heat treatment furnace, the temperature in the reactor and boiler inspection and control, medical electronics and other biochemical analyzer, internalare related to temperature control, has a special broad prospects. Key words: AT89S51 monolithic integrated circuit temperature sensor DS18B20 SJA1000 controller temperature examination 基于 CAN 總線的溫度檢測系統(tǒng) VI 目 錄 引 言 ............................................................................................................................. 1 第 1 章 緒 論 ................................................................................................................. 2 本設(shè)計研究的背景和實際意義 .................................................................................... 2 研究相關(guān)內(nèi)容的現(xiàn)狀 .................................................................................................. 2 課題完成功能 .............................................................................................................. 3 第 2 章 系統(tǒng)設(shè)計的基本方案 ............................................................................................. 4 設(shè)計的主要思路 ............................................................................................................. 4 溫度檢測的總體方案設(shè)計 .............................................................................................. 4 第 3 章 CAN 總線溫度檢測系統(tǒng)的硬件及設(shè)計 .................................................................. 5 CAN總線的介紹 ............................................................................................................. 5 AT89S51單片機(jī)介紹 ...................................................................................................... 6 傳感器的選用 DS18B20 傳感器 ....................................................................................... 8 收發(fā)器，控制器與光耦合器 .......................................................................................... 11 CAN總線接口電路設(shè)計 ................................................................................................. 13 單片機(jī)的接口電路 ........................................................................................................ 15 第 4 章 軟件設(shè)計 ............................................................................................................. 19 軟件流程圖 .................................................................................................................. 19 系統(tǒng)程序設(shè)計 ............................................................................................................... 23 實驗結(jié)果分析 ............................................................................................................... 23 結(jié)論與展望 ......................................................................................................................... 24 致 謝 ................................................................................................................................. 25 參考文獻(xiàn) ............................................................................................................................. 26 附錄 A 原理圖 ..................................................................................................................... 27 附錄 B 一篇引用的外文文獻(xiàn)及其譯文 ............................................................................. 28 附錄 C 列入的主要參考文獻(xiàn)的題錄及摘要 .................................................................... 30 附錄 D 實驗的部分主要源程序 ........................................................................................ 31 VII 插圖清單 圖 21 系統(tǒng) 結(jié)構(gòu)圖 ............................................................................................................. 4 圖 31 AT89S51 單片機(jī)引腳圖 ......................................................................................... 6 圖 32 DS18B20 外形結(jié)構(gòu)圖 ............................................................................................. 9 圖 33 DS18B20 的 寫時序 ............................................................................................... 10 圖 34 DS18B20 的讀時序 ............................................................................................... 10 圖 35 PCA82C250 收發(fā)器 .............................................................................................. 11 圖 36 CAN 總線系統(tǒng)硬件電路原理圖 ......................................................................... 14 圖 37 振蕩電路 ................................................................................................................ 15 圖 38 外部 時鐘的電路 ......................