【正文】 畢業(yè)論文（設(shè)計(jì)）基于單片機(jī)的糧倉溫濕度監(jiān)控系統(tǒng)的設(shè)計(jì)系 別 自動(dòng)化工程系 專業(yè)名稱 自 動(dòng) 化 班級(jí)學(xué)號(hào) 5060509 學(xué)生姓名 衛(wèi) 一 恒指導(dǎo)教師 劉 云 靜 老師 2010 年 06 月 16 日東北大學(xué)秦皇島分校畢業(yè)設(shè)計(jì)（論文） 第 I 頁基于單片機(jī)的糧倉溫濕度監(jiān)控系統(tǒng)的設(shè)計(jì)摘 要在糧食的儲(chǔ)藏的過程中，由于糧倉溫濕度異常而造成糧食變質(zhì)，帶來的經(jīng)濟(jì)損失是 驚人的。目前我國許多糧食倉儲(chǔ)單位采用測溫儀器與人工抄錄、管理相結(jié)合的傳統(tǒng)方法， 消耗了大量的人力和財(cái)力，并且效果不佳，發(fā)霉變質(zhì)等現(xiàn)象大量存在。因此設(shè)計(jì)智能糧 倉溫濕度監(jiān)控系統(tǒng)，提高了工作效率，實(shí)現(xiàn)糧倉溫濕度的實(shí)時(shí)監(jiān)控，是倉儲(chǔ)單位亟待解 決的重要問題。在實(shí)際的生產(chǎn)過程中，溫濕度監(jiān)控問題是一個(gè)很復(fù)雜的問題。本文通過全面分析溫 濕度監(jiān)控問題的特點(diǎn)以及國內(nèi)外研究發(fā)展?fàn)顩r，提出了一種溫濕度監(jiān)控系統(tǒng)的設(shè)計(jì)方 法。該系統(tǒng)采用單片機(jī)自動(dòng)檢測糧倉溫濕度信息，并通過CAN總線與上位機(jī)進(jìn)行通信， 來解決糧倉內(nèi)溫度和濕度的實(shí)時(shí)檢測和可靠控制的問題。進(jìn)而根據(jù)問題的特殊性，在檢 測、存儲(chǔ)和控制實(shí)現(xiàn)上，都做了改進(jìn)，使問題可以在一個(gè)可行的時(shí)間范圍內(nèi)得到解決。 在仿真和模擬試驗(yàn)中，驗(yàn)證了該系統(tǒng)的可行性，分析了該系統(tǒng)在解決實(shí)際問題時(shí)的不足， 并提出了改進(jìn)的辦法。每個(gè)糧倉設(shè)有一個(gè)智能節(jié)點(diǎn)，該節(jié)點(diǎn)以 STC89C52 單片機(jī)為核心,主要完成糧倉內(nèi)溫 濕度的采集，處理，顯示并做出判斷實(shí)現(xiàn)超限報(bào)警和無差控制，還通過 CAN 總線傳至 上位機(jī)有關(guān)信息。上位機(jī)通過接收智能節(jié)點(diǎn)傳來的信息，了解各糧倉溫濕度情況，并且 能根據(jù)各智能節(jié)點(diǎn)地址，設(shè)定任何一個(gè)糧倉溫濕度的報(bào)警閾值，從而解決了多個(gè)糧倉的 溫濕度監(jiān)控問題。最后，對論文工作進(jìn)行了總結(jié)，并說明了進(jìn)一步開發(fā)和研究的方向。關(guān)鍵詞：糧倉，溫濕度控制，CAN 總線東北大學(xué)秦皇島分校畢業(yè)設(shè)計(jì)（論文）第 5 頁The Design of Barn?s Temperature and Humidity MonitorSystem based on SCMAuthor：Wei Yi HengTutor：Liu YunJingAbstractIn the process of grain storage, grain deteriorates due to the abnormal of the barn?s temperature and humidity, and the economic losses which brought about are amazing. At present many grain storage units in our country use the traditional methods which is bined of thermometer device, artificial transcription and artificial management, consuming a lot of manpower and financial resources, and the results are poor, the phenomena of mildewing and metamorphism exists in large quantities. Therefore, designing the temperature and humidity monitor system on barn, improving efficiency and achieving realtime monitoring of barn?s temperature and humidity, is an important problem demanding prompt solution by storage units.In the actual production process, the monitoring of temperature and humidity?s is a very plex issue. In this paper, a method of designing the barn?s temperature and humidity monitor system after fully analysis the characteristics of temperature and humidity monitor issues and domestic and the research and development status both at home and abroad. The system uses microputer to detect the temperature and humidity information automatic, municate with the host puter by the CAN bus and solve the problem of temperature and humidity?s realtime detection and reliable control in the barn. Then according to the specificity of problem, an improvement is made on detection, storage and control?s realizing, which solves the problem reasonably in relatively short time. In the simulation, the feasibility of the system is verified, the shortage of this system when processing actual problem is also analyzed and the new improvement is raised.Each barn has an intelligent node, which is based on STC89C52 microcontroller mainly plete the collection and processing of temperature and humidity inside the barn, anddisplay and make judgments on the overlimit alarm and No difference control. It also deliver the relevant information to PC by the CAN bus. Host puter find out each barn? s temperatures and humidity through the information ing from intelligent nodes, and set temperature and humidity alarm threshold in every ban based due to every intelligent node?s address, and therefore the problem on Multiple barn?s temperature and humidity monitor has been solved.In the end, the work in this paper is summarized and the further step of this research is clarified.Key Words: barn, temperature and humidity control, CANbus目 錄1 緒論 ............................................................................................................................ 1 背景....................................................................................................................... 1 國內(nèi)外研究現(xiàn)狀與發(fā)展趨勢............................................................................... 3 設(shè)計(jì)的目的及意義............................................................................................... 4 設(shè)計(jì)的主要工作................................................................................................... 5 本文的研究內(nèi)容................................................................................................... 52 方案選擇與總體設(shè)計(jì) ................................................................................................ 6 溫濕度的相關(guān)概念............................................................................................... 6 溫濕度的測量方法............................................................................................... 8 溫濕度傳感器的選取........................................................................................... 9 系統(tǒng)總體設(shè)計(jì)..................................................................................................... 103 系統(tǒng)硬件設(shè)計(jì) .......................................................................................................... 15 STC89C52 簡介.................................................................................................. 15 數(shù)據(jù)采集電路..................................................................................................... 16 DHT21 性能說明......................................................................................... 17 DHT21 引腳介紹......................................................................................... 18 DHT21 數(shù)據(jù)格式......................................................................................... 18 DHT21 時(shí)序................................................................................................. 18 鍵盤輸入電路..................................................................................................... 20 LCD 顯示電路 .................................................................................................... 21 電路概述 ...................................................................................................... 21 LCD1602 引腳 ............................................................................................. 21 LCD160