【正文】 目 錄摘要 ....................................................................IIIABSTRACT.................................................................IV1 緒論 ....................................................................1 論文研究的背景和意義 ................................................1 電冰箱電控系統(tǒng)的發(fā)展現(xiàn)狀 ............................................2 論文主要設(shè)計(jì)內(nèi)容 ....................................................22 總體設(shè)計(jì)方案 ............................................................4 總體設(shè)計(jì)方案簡(jiǎn)介 ....................................................4 電冰箱電控系統(tǒng)的主要功能和要求 ......................................53 系統(tǒng)硬件設(shè)計(jì) ............................................................6 AT89C51 單片機(jī)最小系統(tǒng) ...............................................6 AT89 系列單片機(jī)的概況 ............................................6 時(shí)鐘電路.........................................................9 復(fù)位電路........................................................10 單片機(jī)系統(tǒng)電源設(shè)計(jì)..............................................12 霜厚檢測(cè)電路 .......................................................14 熱敏電阻簡(jiǎn)介....................................................14 運(yùn)算放大器 LM324................................................15 霜厚檢測(cè)電路....................................................16 冷凍室冷藏室溫度檢測(cè)采樣電路 .......................................17 溫度傳感器 AD590................................................17 ADC0809 簡(jiǎn)介....................................................18 冷凍室溫度采樣電路圖............................................20 冷藏室溫度采樣電路圖............................................20 冷凍室冷藏室溫度檢測(cè)采樣原理....................................21 過(guò)欠壓保護(hù)電路..................................................21 ADC0809 與 AT89C51 接口設(shè)計(jì) ..........................................22 地址鎖存器 74LS373..............................................22 ADC0809 與 AT89C51 的接口電路 ....................................23 制冷與除霜控制電路 .................................................24 鎖存器 74LS273..................................................24 驅(qū)動(dòng)控制電路的設(shè)計(jì)..............................................25 開(kāi)門(mén)報(bào)警電路 .......................................................26 鍵盤(pán)顯示電路 .......................................................26 接口芯片 8279 簡(jiǎn)介...............................................26 LED 簡(jiǎn)介 ........................................................28 鍵盤(pán)顯示電路設(shè)計(jì)................................................294 系統(tǒng)軟件設(shè)計(jì) ...........................................................31 系統(tǒng)主程序 .........................................................31 T0 中斷服務(wù)程序 .....................................................32 T1 中斷服務(wù)程序 .....................................................33 INT0 中斷服務(wù)程序 ...................................................335 結(jié)論 ...................................................................35參考文獻(xiàn) .................................................................36致謝 .....................................................................37摘 要單片機(jī)即單片微型計(jì)算機(jī)（SingleChip Microputer ），是集 CPU,RAM,ROM,定時(shí)，計(jì)數(shù)和多種接口于一體的微控制器。其中 51 單片機(jī)是各種單片機(jī)中最為典型和最有代表性的一種,廣泛應(yīng)用于各個(gè)領(lǐng)域。 本課題設(shè)計(jì)的電冰箱的電控系統(tǒng)主要應(yīng)用 AT89C51 單片機(jī)作為核心控制元件進(jìn)行分析和設(shè)計(jì)，對(duì)各部分的軟件編程、硬件電路設(shè)計(jì)、及調(diào)試進(jìn)行了介紹。本系統(tǒng)分溫度測(cè)量和信號(hào)產(chǎn)生輸出兩大部分。溫度測(cè)量部分以模擬電路為主，配合電壓比較模塊、A/D 轉(zhuǎn)化模塊，在誤差允許范圍內(nèi)測(cè)量溫度值，并進(jìn)行比較 ,產(chǎn)生電壓信號(hào)。信號(hào)經(jīng) A/DC0809 進(jìn)行 A/D 轉(zhuǎn)換，進(jìn)入 AT89C51 單片機(jī)。信號(hào)經(jīng)單片機(jī)的控制運(yùn)算處理，產(chǎn)生控制信號(hào)并輸出控制壓縮機(jī)、加熱器的啟動(dòng)與停止。此外，該系統(tǒng)可通過(guò)專用鍵盤(pán)接口芯片 8279 進(jìn)行溫度的設(shè)定及顯示。系統(tǒng)擴(kuò)展 LED 顯示器，顯示動(dòng)態(tài)的冷凍室溫度和冷藏室溫度；系統(tǒng)擴(kuò)展了多個(gè)功能鍵，通過(guò)功能鍵可人為改變控制設(shè)定值從而滿足不同用戶的不同需要。近年來(lái)，隨著微電子技術(shù)、傳感器技術(shù)以及計(jì)算機(jī)控制技術(shù)的發(fā)展，人們對(duì)電冰箱的控制功能要求越來(lái)越高，這對(duì)電冰箱控制器提出了更高的要求，多功能、人性化和節(jié)能是其發(fā)展方向。傳統(tǒng)的機(jī)械式、簡(jiǎn)單的電子控制已經(jīng)難以滿足發(fā)展要求。為此，本文介紹了采用 AT89C51 單片機(jī)作為控制器核心，對(duì)電冰箱的工作過(guò)程進(jìn)行控制，并用聲音將電冰箱的一些工作過(guò)程進(jìn)行提示，使控制過(guò)程更人性化。通過(guò) AD590 溫度傳感器對(duì)冷藏室溫度,冷凍室溫度進(jìn)行檢測(cè)，并將產(chǎn)生的模擬信號(hào)，通過(guò) ADC0809 進(jìn)行A/D 轉(zhuǎn)換送入單片機(jī)；對(duì)霜厚度則通過(guò)熱敏電阻進(jìn)行溫度檢測(cè)后產(chǎn)生中斷信號(hào)送入單片機(jī)。溫度檢測(cè)信號(hào)經(jīng)單片機(jī)處理后用語(yǔ)調(diào)節(jié)壓縮機(jī)和加熱器的工作，滿足消費(fèi)者對(duì)溫度的設(shè)置要求，實(shí)現(xiàn)自動(dòng)除霜功能。經(jīng)過(guò)實(shí)踐證明，經(jīng)過(guò)反復(fù)的模擬運(yùn)行、調(diào)試，修改，最后形成了一套完整的程序系統(tǒng)。本系統(tǒng)運(yùn)行穩(wěn)定，其優(yōu)點(diǎn)是硬件電路簡(jiǎn)單，軟件功能完善，控制系統(tǒng)可靠，性價(jià)比較高等，具有一定的實(shí)用和參考價(jià)值。關(guān)鍵詞：AT89C51 單片機(jī),A/DC0809,8279，AD590，電冰箱的電控系統(tǒng)。AbstractSCM is microputer (SingleChip Microputer) which is a set of CPU, RAM, ROM, the timing, number and variety of integrated microcontroller interface. The 51 microprocessor which is quite typical and representative is widely used in various fields. The main topics designed by chip – microputer AT89C51 finish the function of controlling the fridge. This paper introduces the electric refrigerator’s electrically controlled system, including software, hardware design, and missioning the problems encountered in design as well as solutions.The system is dissolved into temperature measurement and signal output two most voltage measurement parts in the main circuit simulation, and tie parative module, A/D conversion module. Surplus microprocessor through data processing, in the range of allowable error temperature measurements shows and generates voltage signal. Signal input is sent into A/DC0809 for A/D conversion. Then the signal after conversion enters AT89C51 microprocessor ． The output that has been dealt with is used to control the run and stop of pressor and heater. In addition ，this system can fulfill the function of successive temperature setting by 8279 ,a chip used to control keyboard and show. The design extends LED display, which displays the dynamic environmental temperature and extends a few functional keys that a user can input the appropriate temperature parameter for the special need. In these years, with the development of microprocessors and sensor, the demand of function of fridge is being higher and higher. Users need it has many functions, personallike interface and little waste of power. However, the traditional fridge can not finish all the functions. As a result, this paper introduces the system which uses AT89C51 as the center of the control system, having sound system to remind users. The 51puter gets the temperature parameter from the integration temperature sensor and the ADC0809 that transforms the analog parameter to the digital parameter. Then, the 51put