【正文】 I 摘 要 本文論述了一種基于單片機的多功能參數(shù)檢測系統(tǒng)的設計與實現(xiàn)過程。系統(tǒng)采用了單片機 STC89C52為主控芯片，設計了電流電壓轉換電路，能夠將現(xiàn)場的溫度、壓力、流量、液位等物理量所對應的 420mA 電流信號轉換成 15V的直流電壓信號，并提供給 A/D轉換電路。根據(jù)系統(tǒng)測量的模擬量較多的特點，使用 ADC0809作為 A/D轉換芯片。使用 LCD1602 作為顯示器件，能夠實時顯示采集的溫度、壓力、流量、液位等物理量。同時，系統(tǒng)還設計了參數(shù)設置與報警提示等功能電路。 論文共分三部分介紹了基于單片機的多功能參數(shù)檢測 系統(tǒng)設計過程。第一部分，主要介紹了系統(tǒng)的方案設計，明確了系統(tǒng)的功能要求，給出了系統(tǒng)方案框圖，并對部分元器件的選擇、軟硬件開發(fā)環(huán)境進行了介紹；第二部分，主要介紹了硬件電路的設計過程，包括主要器件的介紹、與單片機接口電路設計思路敘述；第三部分，對軟件部分的設計思路做了介紹，并分別數(shù)據(jù)采集、顯示、按鍵處理等各功能部分設計過程進行了敘述。 關鍵詞 ：單片機；電流電壓轉換； A/D 轉換； LCD1602；聲光報警 II Abstract This paper discusses a kind of multifunctional parameter detection system based on single chip design use the single chip microputer as the controller STC89C52 chip,using current voltage conversion circuit can change the scene of the physical quantities,such as temperature,pressure,flow,level of 420 mA current signal into 15 V voltage signal,and provide for A/D conversion to the characteristics of the measurement system that there are much more analog quantities,ADC0809 is used as A/D conversion chip,using LCD1602 as a display device,can collect realtime display of temperature,pressure,flow and liquid the same time,the system also designed the circuit for parameter setting and sound and light alarming function. This paper is divided into three part introduces multifunctional parameter detection system based on single chip first part,mainly introduced the system design,the functional requirements of system,the system block diagram is given,and the selection of some ponents,hardware and software development environments are introduced。The second part,mainly introduces the design process of hardware circuit,including the main device,single chip microputer interface circuit design ideas of narrative。The third part,the design idea of the software part is presented,and various functions such as data acquisition,display and buttons processing are discusses. Key words: Single chip microputer。 Current voltage conversion。 A/D conversion。 LCD1602。Sound and light alarm III 目 錄 緒 論 .......................................................................................................................................... 1 1 方案設計 .............................................................................................................................. 2 總體框架的設計 ........................................................................................................ 2 單片機開發(fā)環(huán)境的選擇 ............................................................................................ 3 電路圖繪制軟件 .............................................................................................. 3 Keil_C軟件 ...................................................................................................... 4 2 硬件電路設計 ...................................................................................................................... 6 傳感器的選型 ............................................................................................................ 6 單片機最小系統(tǒng)設計 ................................................................................................ 6 單片機的選型 .................................................................................................. 6 時鐘電路與復位電路 ...................................................................................... 8 單片機使用注意事項 .................................................................................... 10 電流電壓轉換電路設計 .......................................................................................... 11 模擬量采集電路設計 .............................................................................................. 13 ADC0809概述 ............................................................................................... 13 ADC0809與單片機接口電路 ....................................................................... 15 顯示電路設計 .......................................................................................................... 16 LCD1602引腳結構 ....................................................................................... 16 LCD1602主要技術參數(shù)及特性 ................................................................... 16 LCD1602與單片機的接口電路 ................................................................... 17 按鍵接口電路設計 .................................................................................................. 17 報警電路設計 .......................................................................................................... 18 串行口功能設計 ...................................................................................................... 19 RS232串行接口 ........................................................................................... 19 MAX232簡介 ................................................................................................ 20 3 軟件部分設計 .................................................................................................................... 22 主程序工作流程 ...................................................................................................... 22 A/D轉換子程序 ...................................................................................................... 23 數(shù)字濾波及標度變換程序設計 .............................................................................. 24 IV 顯示程序設計 .......................................................................................................... 25 按鍵處理程序設計 .................................................................................................. 27 報警程序設計 .......................................................................................................... 28 結 論 ...............................................................................................................