【正文】 water temperature monitoring system to control the water temperature in the boiler, and choosing proper control rules to make water temperature in the boiler change within the predetermined path, with the function of alerting temperature rising limit. Through the keyboard and display, we can set the goal temp. and other parameters. Control system, according to the functions, includes temperature sensor module, the temperature display / setting module, a temperature control module, MCU and host puter munication module. System can preset the resistance furnace temperature and heating time through the keyboard. Singlechip microputer, according to the furnace temperature and preset temperature and the set of algorithms, calculates the volume control, and according to the control volume, using the PWM control solid state relay to switch on and off so as to control the resistance wire conduction time in order to achieve temperature control. In addition through the serial port of MCU and host puter munication, through the PC software, the device can fulfill the realtime display of current temperature and temperature history and draw out the temperature curve, making the system more readable, realizing the remote monitoring function. Key words: STC89C52, DS18B20, PWM, PC 河南城建學(xué)院本科畢業(yè)設(shè)計(jì)（論文） 目錄 III 目錄 摘 要 .............................................................. ..I Abstract ............................................................. II 目錄 ................................................................ III 1 緒論 ................................................................ 1 選題意義 ......................................................... 1 國(guó)內(nèi)外發(fā)展趨勢(shì) ................................................... 1 系統(tǒng)的主要性能指 標(biāo) ............................................... 2 主要工作任務(wù) ..................................................... 2 2 系統(tǒng)方案選擇和工作原理 ............................................... 3 系統(tǒng)綜述 ......................................................... 3 ........................................ 3 系統(tǒng)硬件總框圖 ............................................. 3 ............................................... 4 ............................................... 4 ............................................... 5 ................................................... 5 ................................................. 5 ......................................... 6 3 系統(tǒng)硬件設(shè)計(jì) ........................................................ 7 STC89C52構(gòu)成的最小系統(tǒng) ........................................... 7 晶振回路 .................................................. 7 復(fù)位電路 .................................................. 8 ............................................ 8 DS18B20概述 ..................................... 8 .................................... 10 報(bào)警電路設(shè)計(jì) .................................................... 10 電源電路設(shè)計(jì) .................................................... 11 按鍵電路設(shè)計(jì) .................................................... 12 ................................ 12 ...................................... 13 顯示電路設(shè)計(jì) .................................................... 13 LCD1602簡(jiǎn)介 ............................................. 13 河南城建學(xué)院本科畢業(yè)設(shè)計(jì)（論文） 目錄 IV LCD1602管腳功能介紹 ..................................... 14 ........................................ 17 時(shí)鐘電路設(shè)計(jì) .................................................... 18 DS1302簡(jiǎn)介 ............................................... 18 DS1302的結(jié)構(gòu)及工作原理 .................................. 18 DS1302的控制字節(jié) ......................................... 18 (I/O) ......................................... 18 DS1302的寄存器 ........................................... 19 DS1302硬件連接圖 ......................................... 19 ................................................ 19 RS232標(biāo)準(zhǔn)介紹 ........................................... 19 DB9連接器 ............................................... 20 MAX232芯片介紹 ........................................... 21 串口硬件連接圖 ............................................ 21 繼電器驅(qū)動(dòng)電路設(shè)計(jì) .............................................. 22 固態(tài)繼電器的分類與工作原理 ................................ 22 .................................... 23 4 系統(tǒng)的軟件設(shè)計(jì) ..................................................... 25 主程序的設(shè)計(jì) .................................................... 25 液晶顯示模塊 .................................................... 27 ................................................ 27 DS18B20測(cè)溫?cái)?shù)據(jù)的讀取程序設(shè)計(jì) ............................ 27 DS18B20溫度讀取流程 ...................................... 32 .................................................... 32 .................................................. 33 5 系統(tǒng)抗干擾措施 ..................................................... 37 .................................................. 37 結(jié) 論 ................................................................ 39 致 謝 ................................................................ 39 參考文獻(xiàn) ............................................................. 40 附錄 A 系統(tǒng)原理圖 ..................................................... 41 附錄 B 系統(tǒng)總程序 ..................................................... 43 河南城建學(xué)院本科畢業(yè)設(shè)計(jì)（論文） 緒論 1 1 緒論 選題意義 隨著現(xiàn)代科學(xué)技術(shù)的迅猛 發(fā)展，各個(gè)領(lǐng)域?qū)囟瓤刂葡到y(tǒng)的精度、穩(wěn)定性等的要求越來(lái)越高，控制系統(tǒng)也千變?nèi)f化?？赏ㄟ^(guò)鍵盤 ，顯示電路設(shè)定目標(biāo)溫度 和 參數(shù)。河南城建學(xué)院本科畢業(yè)設(shè)計(jì)（論文） 摘要 I 摘 要 在現(xiàn)代工業(yè)生產(chǎn)中，人們需要對(duì)各類加熱爐、 反應(yīng)爐和鍋爐中的溫度進(jìn)行檢測(cè)和控制?？刂葡到y(tǒng)按功能分主要包括溫度傳感器模塊、溫度顯示 /設(shè)定模塊、溫度控制模塊 、 單片機(jī)與上位機(jī)通信模塊。例如：在冶金工業(yè)、化工生產(chǎn)、電力工程、造紙行業(yè)、機(jī)械制造和食品加工等諸多領(lǐng)域中，人們都需要對(duì)各類加熱爐、熱處理爐、反應(yīng)爐和鍋爐中的溫度進(jìn)行檢測(cè)和控制等等。而采用單片機(jī)進(jìn)行爐溫控制，不僅可以大大地提高控制質(zhì)量和自動(dòng)化水平，而且具有良好的經(jīng)濟(jì)效益和推廣價(jià)值。其特點(diǎn)是適應(yīng)于大慣性、大滯后等復(fù)雜溫度測(cè)控系統(tǒng)，具有參數(shù)自整定功能