摘 要
隨著單片機(jī)技術(shù)的飛速發(fā)展，單片機(jī)在各個(gè)領(lǐng)域得到了廣泛的應(yīng)用。糧食是人類生存的必需品，溫度是保存好糧食的先決條件，儲(chǔ)存大量的糧食對(duì)穩(wěn)定國(guó)民經(jīng)濟(jì)的發(fā)展起到至關(guān)重要的作用。糧庫一般較大，測(cè)量點(diǎn)會(huì)很多。糧倉溫度測(cè)量方法以及相應(yīng)的智能控制一直是糧食保存的一個(gè)重要問題。
該系統(tǒng)是以AT89C51單片機(jī)和DS18B20數(shù)值溫度傳感器為核心組成的糧倉溫度控制系統(tǒng)。該系統(tǒng)利用AT89C51單片機(jī)采集了各個(gè)溫度點(diǎn)的溫度，實(shí)現(xiàn)溫度顯示、報(bào)警等功能。它以AT89C51單片機(jī)為主控制芯片，采用數(shù)字溫度傳感器DS18B20實(shí)現(xiàn)多路溫度的檢測(cè)，利用LCD1602液晶顯示器形象直觀的顯示測(cè)出的溫度值。本文在確定法設(shè)計(jì)方案基礎(chǔ)上，著重論述了系統(tǒng)的軟硬件設(shè)計(jì)，并且描述了系統(tǒng)電路設(shè)計(jì)、硬件設(shè)計(jì)框圖及所使用各種芯片功能和特性。通過PROTEUS軟件和KEIL C仿真出了該系統(tǒng)。
　　
關(guān)鍵詞：?jiǎn)纹瑱C(jī) DS18B20 液晶顯示 鍵盤 報(bào)警










Temperature Control System Of The Granary Based On Single-chip
Author：Mu Xiqing Tutor：Fan Lina
Abstract
Along with the single chip microcomputer technology rapid development, the microcontroller obtained the widespread application in each domain. The grain is the human survival essential item，the temperature is the precondition of preserving the grain well, storing up the massive grain plays a crucial role in the development of the stable national economy. Provision room is generally big, so there will be a lot of measurement points. Grain temperature measurement method and the corresponding intelligent control of food preservation has been an important issue.
The system is based on AT89C51 single-chip and numerical temperature sensor DS18B20, which composite the core temperature control system. This system has gathered each temperature using AT89C51 monolithic integrated circuit, which realizes functions temperature display and alarm functions and so on. It takes AT89C51 monolithic integrated circuit as main control chip, which uses digit temperature sensor DS18B20 to realize the multi-channel temperature detections. Temperature value which determines is displayed using the LCD1602 liquid-crystal in direct-viewing demonstration. This article focuses on system's software and hardware design emphatically on the foundation of determining the design of the program. It describes the system circuit design, the hardware design diagram as well as the function and the characteristic of the chip which is used in the system. This system is simulated through the PROTEUS and KEIL C software.

Key Words: Single-chip Microcomputer DS18B20 Liquid-crystal display
Keyboard Warning

目錄
一 緒論 1
1.1背景 1
1.2設(shè)計(jì)的目的和意義 1
1.3相關(guān)領(lǐng)域國(guó)內(nèi)外技術(shù)和發(fā)展趨勢(shì) 2
二 系統(tǒng)方案設(shè)計(jì) 4
2.1方案設(shè)計(jì) 4
3.2方案論證 5
三 溫度傳感器 6
3.1溫度傳感器的選型 6
3.1.1傳感器的選擇原則 6
3.1.2溫度傳感器的選擇 6
3.2 溫度上、下限值的設(shè)定原理 7
四 系統(tǒng)硬件設(shè)計(jì) 8
4.1系統(tǒng)工作原理綜述 8
4.2 DS1820與單片機(jī)接口電路 9
4.2.1單片機(jī)89C51為本系統(tǒng)的核心 10
4.2.2中央處理器AT89C51簡(jiǎn)介 13
4.3 DS18B20簡(jiǎn)介及測(cè)溫電路設(shè)計(jì) 16
4.3.1 DS18B20 的性能特點(diǎn) 17
4.3.2 DS18B20的外形和內(nèi)部結(jié)構(gòu) 17
4.3.3高速暫存存儲(chǔ)器 21
4.3.4 DS18B20單總線(1一Wire)的基本原理 22
4.4液晶顯示電路 29
4.4.1 LCD1602主要技術(shù)參數(shù) 29
4.4.2 LCD1602的引腳說明 30
4.4.3控制指令說明 30
4.5按鍵電路 31
4.6報(bào)警電路 33
五 軟件功能及框圖 34
5.1主程序 34
5.2 讀出溫度子程序 34
5.3 溫度轉(zhuǎn)換命令子程序 34
5.4 計(jì)算溫度子程序 34
5.5顯示數(shù)據(jù)刷新程序子程序 34
5.6按鍵處理子程序 34
六 單片機(jī)的抗干擾問題 40
6.1干擾因素 40
6.2硬件抗干擾措施 40
6.2.1合理選擇元器件 40
6.2.2電源干擾的抑制 40
6.2.3電場(chǎng)、磁場(chǎng)干擾的抑制 40
6.2.4接地技術(shù) 40
6.2.5通道技術(shù) 41
6.2.6布線抗干擾設(shè)計(jì) 42
6.3軟件抗干擾措施 43
6.3.1數(shù)字濾波器 43
6.3.2軟件冗余 43
6.3.3設(shè)置軟件陷阱 43
6.3.4重要指令冗余 43
6.3.5“看門狗”技術(shù) 43
結(jié)論 45
參考資料 46
致謝 47
附錄1 仿真原理圖 48
附錄2 程序代碼 49
附錄3 英文文獻(xiàn) 67