【正文】 ............................................................. 6 CPU 字長的選擇 ............................................................................. 7 系統(tǒng)方案組成 ............................................................................................ 7 第 3 章 系統(tǒng)的硬件設(shè)計 ....................................................................................... 10 器件的選型 .............................................................................................. 10 單片機的選型 ............................................................................... 10 溫度傳感器的選擇 ....................................................................... 11 濕度傳感器的選擇 ....................................................................... 12 液位傳感器的選擇 ....................................................................... 12 A/D 轉(zhuǎn)換器件的選擇 .................................................................... 14 顯示器件的選擇 ........................................................................... 14 加熱器件的選擇 ........................................................................... 14 壓縮機的選型 ............................................................................... 15 加濕器的選型 ............................................................................... 16 總線結(jié)構(gòu)的選擇 ...................................................................................... 16 濕度信息采集電路設(shè)計 .......................................................................... 17 溫度信息采集電路設(shè)計 .......................................................................... 18 液位信息采集電路設(shè)計 .......................................................................... 19 A/D 轉(zhuǎn)換電路 ........................................................................................... 20 顯示電路 .................................................................................................. 21 鍵盤輸入電路 .......................................................................................... 22 現(xiàn)場總線 .................................................................................................. 22 CAN 總線特點 .............................................................................. 22 本科生畢業(yè)設(shè)計（論文） IV CAN 總線協(xié)議 .............................................................................. 23 電源電路 ................................................................................................ 25 單片機外圍電路設(shè)計 ............................................................................ 26 通信接口電路設(shè)計 ................................................................................ 27 驅(qū)動電路設(shè)計 ........................................................................................ 28 報警電路設(shè)計 ........................................................................................ 29 監(jiān)控室通信接口電路設(shè)計 .................................................................... 30 第 4 章 軟件設(shè)計 ................................................................................................... 31 主程序設(shè)計 .............................................................................................. 31 信息采集子程序設(shè)計 .............................................................................. 32 鍵盤信息采集子程序設(shè)計 ...................................................................... 34 CAN 總線通信子程序設(shè)計 ..................................................................... 35 顯示子程序設(shè)計 ...................................................................................... 38 控制子程序設(shè)計 ...................................................................................... 40 串行通信子程序設(shè)計 .............................................................................. 42 第 5 章 總 結(jié) ......................................................................................................... 45 設(shè)計中出現(xiàn)的問題及解決方案 .............................................................. 45 關(guān)于設(shè)計的總結(jié) ...................................................................................... 45 致謝 ......................................................................................................................... 47 參考文獻 ................................................................................................................. 48 附錄Ⅰ ..................................................................................................................... 49 附錄Ⅱ ..................................................................................................................... 52 附錄Ⅲ ..................................................................................................................... 63 本科生畢業(yè)設(shè)計（論文） 1 第 1章 緒論 題目的來源與意義 溫濕度試驗箱能夠提供一個高溫環(huán)境或低溫環(huán)境，主要用于考核產(chǎn)品在高低溫環(huán)境中的性能。 本設(shè)計實現(xiàn)了基于單片機溫濕度試驗箱的設(shè)計 ， 采用該方案 設(shè)計的溫濕度試驗箱具有低功耗、高效能等特點，具有很高的安全性、經(jīng)濟性和可靠性。 本科生畢業(yè)設(shè)計（論文） I 摘 要 溫濕度實驗箱在現(xiàn)實生活中有著廣泛的應(yīng)用，溫濕度實驗箱能夠提供一個恒濕或恒溫的環(huán)境，能夠?qū)崿F(xiàn)溫度和濕度的連續(xù)可調(diào)，汽車摩托、航天航空、船舶兵器等都需要進行溫度和適度的實驗，以檢驗其各項性能指標(biāo)的穩(wěn)定性。 關(guān)鍵詞： 溫濕度；試驗箱；單片機； CAN 總線 本科生畢業(yè)設(shè)計（論文） II Abstract Temperature and humidity test box is widely used in real life, the temperature and humidity test box can provide a constant humidity or temperature environment, continuously adjustable to achieve temperature and humidity, automobile motor, aerospace, weapons, ships need experimental temperature and moderate, to test their stabilities of various performance indicators. In this paper, the design system is divided into equipment and control room equipment two parts, to every part of the design of software and hardware, the system with RS232 munication interface circuit, CPU part uses AT89S52 microcontroller, temperature sensor using AD590 temperature sensor, humidity sensor using the relative humidity sensor HIH36101 of Honeywell, a munication module based on CAN bus munication transmission. The control room by PC for display and control, in the part of software design of the main program, the lower puter information acquisition subprogram