【正文】 ure and humidity is an important physical quantity, is the most mon and important technical parameters in grain storages. With the progress of the times, the development of society, science and technology unceasing renewal, the temperature and humidity measurement accuracy requirements continue to increase, so the temperature and humidity detection has bee an important research topic. The design and implementation of measurement and control temperature and humidity is MCU system, through which the temperature and humidity measurement liquid crystal displays (LCD). System adopts set temperature and humidity sensor and A/D converter for SHT11 chip microcontroller processing, through that other modules including realtime clock/date produce circuit and the offgauge alarm circuit, the value of measurement for realtime display and alarm. The paper introduces the ATMEL pany based on AT89C51 singlechip series of temperature and humidity measurement and control system and realtime display system design, including the hardware structure and principle, and the corresponding software design, including the design of the software and its key process and procedure. System structure is simple, practical, and improve the measuring precision and efficiency. Key Words: MCU, SHT11, LCD, DS1302, Temperature and humidity control 蘭州交通大學(xué)畢業(yè)設(shè)計(jì)（論文） III 目 錄 摘 要 ..................................................................................................................................... I Abstract ...................................................................................................................................... II 目 錄 ...................................................................................................................................III 1 緒論 ........................................................................................................................................ 1 問題的提出背景及研究意義 ..................................................................................... 1 國內(nèi)外現(xiàn)狀 ................................................................................................................. 2 課題的研究目的及內(nèi)容 ............................................................................................. 3 2 控制系統(tǒng)的硬件電路設(shè)計(jì) .................................................................................................... 4 整體設(shè)計(jì)方案 ............................................................................................................. 4 微控制器模塊 ............................................................................................................. 4 復(fù)位電路設(shè)計(jì) .................................................................................................. 4 時(shí)鐘電路設(shè)計(jì) .................................................................................................. 5 傳感電路設(shè)計(jì) ............................................................................................................. 6 顯示電路設(shè)計(jì) ............................................................................................................. 9 超限處理電路設(shè)計(jì) ................................................................................................... 12 硬件電路 PCB 版圖設(shè)計(jì) ......................................................................................... 12 3 控制系統(tǒng)的軟件設(shè)計(jì) .......................................................................................................... 14 軟件開發(fā)平臺(tái)介紹 ................................................................................................... 14 主程序流程設(shè)計(jì) ....................................................................................................... 15 溫濕度采集及處理流程設(shè)計(jì) ................................................................................... 16 LCD 顯示流程設(shè)計(jì) .................................................................................................. 17 超限處理流程設(shè)計(jì) ................................................................................................... 17 4 仿真與調(diào)試 .......................................................................................................................... 18 仿真軟件介紹 ........................................................................................................... 18 系統(tǒng)的調(diào)試 ............................................................................................................... 18 結(jié) 論 .................................................................................................................................. 21 致 謝 .................................................................................................................................. 22 參考文獻(xiàn) .................................................................................................................................. 23 附錄 A 系統(tǒng)程序 .................................................................................................................... 24 蘭州交通大學(xué)畢業(yè)設(shè)計(jì)（論文） 1 1 緒論 問題的提出背景 及研究意義 農(nóng)業(yè)是國 民 經(jīng)濟(jì)的基礎(chǔ)，糧食是基礎(chǔ)的基礎(chǔ)。中央糧食儲(chǔ)備有較為完善的倉儲(chǔ)設(shè)施 和 技術(shù)保障，在保證國家糧食安全方面發(fā)揮著重要作用。長期以來由于種種原因，忽視了農(nóng)戶糧食儲(chǔ)藏技術(shù)的研究與推廣，農(nóng)戶糧食的儲(chǔ)藏技術(shù)非常落后 ， 給國家和人民造成了巨大 的損失 ， 與此同時(shí)糧食產(chǎn)量增長所依賴的資源正在告急，如耕地面積進(jìn)一步減少，水土流失日益嚴(yán)重 ， 生態(tài)平衡遭到破壞 ， 人口仍在增長的狀況 ， 而提高糧食總產(chǎn)量的空間已很小 ，并且 我國到 2040 年人口將達(dá)到 億 ， 根據(jù)我國現(xiàn)有的光、熱 、 水、土和氣候資源，中國科學(xué)院在《我國土地的人口承載能力研究》中指出：我國糧食最大可能生產(chǎn)能力為 億噸，按聯(lián)合國確定的最低標(biāo)準(zhǔn)人均 500kg 計(jì)， 億人口是我國國土的人口承載能力的極限。在這樣一種大形勢下，國家投資興建了大型現(xiàn)代化糧庫 ， 最大糧庫方圓幾公里，倉庫房數(shù)為數(shù)十個(gè)。主要存在問題有如何隨時(shí)掌握每個(gè)倉內(nèi)糧食的質(zhì)量變化情況，保證入庫的糧食在較長時(shí)間的保存期內(nèi)不變質(zhì)。環(huán)境控制工程作為農(nóng)業(yè)生物速生、優(yōu)質(zhì)、高產(chǎn)的手段，是農(nóng)業(yè)現(xiàn)代化的重要標(biāo)志。因此，采用先進(jìn)的人工智能技術(shù)，科學(xué)、合理地控制影響作物的環(huán)境因子，通過計(jì)算機(jī)控制設(shè)備進(jìn)行環(huán)境控制，以便給作物生長創(chuàng)造一個(gè)最佳的環(huán)境條件，做到既提高產(chǎn)品的質(zhì)量、產(chǎn)量、經(jīng)濟(jì)價(jià)值和社會(huì)效益， 又 盡量降低生產(chǎn)成本，這對(duì)糧倉環(huán)境施行自動(dòng)檢測和控制是非常必要的。并且隨著城市居民生活節(jié)奏的加快以及人民生活水平的不斷提高，人們對(duì)于亞健康的問題越來越關(guān)注，因此對(duì)于居住環(huán)境的要求也越來越高，舒適的環(huán)境已不僅僅