摘 要

近年來(lái)，隨著單片機(jī)功能的日益強(qiáng)大和計(jì)算機(jī)的廣泛應(yīng)用，糧情檢測(cè)的準(zhǔn)確性、穩(wěn)定性要求越來(lái)越高。尋找最佳配置和最好的性價(jià)比成為糧情監(jiān)測(cè)研究的熱點(diǎn)。國(guó)外在糧情監(jiān)控技術(shù)己達(dá)到了很成熟的地步，高科技數(shù)字式傳感器廣泛應(yīng)用于糧情檢測(cè)系統(tǒng)。

本課題設(shè)計(jì)的是一種基于單片機(jī)的糧庫(kù)溫度控制系統(tǒng)。實(shí)現(xiàn)了對(duì)糧庫(kù)內(nèi)溫度進(jìn)行時(shí)實(shí)檢測(cè)和控制。

本系統(tǒng)采用美國(guó)Dallas公司最新推出的DS18B20數(shù)字式溫度傳感器，與傳統(tǒng)的熱敏電阻溫度傳感器不同，它輸出的是數(shù)字信號(hào)，從而降低了干擾，電路簡(jiǎn)單，提高了測(cè)量精度。系統(tǒng)下位機(jī)采用AT89S52單片機(jī)，對(duì)采集溫度數(shù)據(jù)進(jìn)行處理，然后進(jìn)行控制，使糧庫(kù)溫度適宜。

關(guān)鍵詞  單片機(jī)  溫度傳感器  RS-485

Abstract

  In recent years, along with the list slice the machine function is increasingly strong with the calculator of extensive application, the accuracy,stability request of the food feeling examination is more and more high.Look for the best install with best of sex price ratio become the food feeling a monitor research of hot point.Abroad at the food feeling supervision technique F come to a very mature of situation, high technology numeral the type spread the feeling machine extensive application in the food feeling examination system.

  This topic design of is a kind of the slice is according to the list the food database temperature of the machine control system.Realization carry on to the food temperature inside the database hour solid examination and control.

  This system adoption the United States the Dallas company is the latest to release of the DS18B20 digital temperature sensor , it is different from tradition of thermistor temperature sensor , its output is digital signal, lower interference thus, electric circuit simple, exaltation measure accuracy.The system next machine adoption AT89 S52 list slice machine, carry on a processing towards collecting the temperature data, then carry on a control, make the food database temperature feat.

Keyword  The list slice machine  temperature sensor  RS-485目錄

摘 要 I

Abstract II

第1章 緒論 1

1.1 課題背景 1

1.2 糧情測(cè)控系統(tǒng)現(xiàn)狀及其發(fā)展 1

1.2.1 糧情測(cè)控系統(tǒng)現(xiàn)狀 1

1.2.2 未來(lái)發(fā)展方向 2

1.3 糧情檢測(cè)技術(shù)的國(guó)內(nèi)外研究動(dòng)態(tài) 3

第2章 系統(tǒng)設(shè)計(jì)原理 5

2.1 溫度檢測(cè)原理 5

2.1.1 溫度測(cè)量的主要方法 5

2.1.2 測(cè)溫常用溫度傳感器 5

2.2 數(shù)據(jù)通信原理 7

2.2.1 內(nèi)部總線 7

2.2.2 外部總線 8

2.3 顯示和鍵盤技術(shù) 9

2.3.1 顯示技術(shù) 9

2.3.2 鍵盤接口 12

第3章 系統(tǒng)硬件設(shè)計(jì) 15

3.1 系統(tǒng)總體方案設(shè)計(jì) 15

3.2 溫度傳感器的設(shè)計(jì) 16

3.3 CPU的選擇 17

3.4 數(shù)碼管顯示電路設(shè)計(jì) 19

3.5 鍵盤電路設(shè)計(jì) 20

3.6 電源電路的設(shè)計(jì) 22

3.7 聲光報(bào)警電路設(shè)計(jì) 22

3.8 系統(tǒng)溫度控制設(shè)計(jì) 23

第4章 系統(tǒng)軟件的設(shè)計(jì) 26

致謝 32

參考文獻(xiàn) 33

附錄1 34

附錄2 40