【正文】 AT89C51 MCU used as a main control unit, this system has the function of displaying the clock, mileage statistics and cost, voicebroadcasting, printing papers, the information of which will be displayed on the LCD screen. From the point of hardware,this system gives the driver and the passengers relevant information about the conditions of the taxi and the different charging rates and charges on different condition by simulating human voice with the voice funtion of ISD1420 , the TG12864E LCD modules, and by simulating the real the point of software,the system is loaded with program in Clanguage. This kind of taximeter provides a new application area for the taxi industry and improves the billing functions. Key Words： AT89C51 MCU； TG12864E LCD Module； C Language III 目 錄 摘 要 ..................................................................................................................................... I Abstract ...................................................................................................................................... II 引 言 .................................................................................................................................... 1 1 緒論 ...................................................................................................................................... 2 出租車計(jì)價(jià)器的發(fā)展概況 ....................................................................................... 2 出 租車行業(yè)的管理現(xiàn)狀 ........................................................................................... 2 計(jì)價(jià)器設(shè)計(jì)需要解決的問題 ................................................................................... 3 2 系統(tǒng)總體介紹 ...................................................................................................................... 4 系統(tǒng)組成 ................................................................................................................... 4 系統(tǒng)各部分功能 ....................................................................................................... 4 里程計(jì)量功能 ................................................................................................ 4 費(fèi)用計(jì)算功能 ................................................................................................ 5 語音播報(bào)功能 ................................................................................................ 5 中文菜單顯示功能 ........................................................................................ 5 實(shí)時(shí)時(shí)鐘功能 ................................................................................................ 6 票據(jù)打印功能 ................................................................................................ 6 按鍵功能 ........................................................................................................ 6 3 系統(tǒng)硬件電路設(shè)計(jì) .............................................................................................................. 7 控制單元及相關(guān)擴(kuò)展電路設(shè)計(jì) ............................................................................... 7 AT89C51 的引腳 ........................................................................................... 7 振蕩器電路 .................................................................................................... 8 里程計(jì)算與計(jì)價(jià)單元的設(shè)計(jì) ...................................................................... 10 擴(kuò)展存儲(chǔ)器的設(shè)計(jì) ...................................................................................... 11 擴(kuò)展 I/O 接口的設(shè)計(jì) ................................................................................... 14 時(shí)鐘模塊 ................................................................................................................. 17 DS12887 時(shí)鐘芯片的性能及引腳說明 ...................................................... 17 AT89C51 與 DS12887 的接口設(shè)計(jì) ............................................................ 19 語音播放模塊 ......................................................................................................... 21 ISD1420 芯片的引腳功能及性能 ............................................................ 21 ISD1420 芯片與 AT89C51 的接口電路 ..................................................... 23 液晶顯示驅(qū)動(dòng)模塊 ................................................................................................. 24 出租車計(jì) 價(jià)系統(tǒng)的設(shè)計(jì) IV TG12864E 液晶模組的功能 ....................................................................... 24 外形尺寸圖 .................................................................................................. 24 結(jié)構(gòu)框圖 ...................................................................................................... 24 模塊的外部接口 .......................................................................................... 25 液晶顯示驅(qū)動(dòng)模塊電路圖 .......................................................................... 26 票據(jù)打印模塊 ......................................................................................................... 27 打印機(jī)的選擇 ............................................................................................. 27 TP P 40A? ? 主要技術(shù)性能及接口要求 ................................................... 28 TP P 40A? ? 與單片機(jī)接口 ....................................................................... 29 按鍵掃描模塊 ......................................................................................................... 29 4 系統(tǒng)軟件設(shè)計(jì) .................................................................................................................... 30 系統(tǒng)主程序及顯示單元流程框圖 ......................................................................... 30 里程和費(fèi)率計(jì)算子程序流程圖 ............................................................................. 31 鍵盤處理子程序流程圖 ......................................................................................... 31 結(jié) 論 ..........................................................................