【正文】 徐州工 程學院畢業(yè)設計（論文） I 圖 書 分類號： 密 級： 摘要 出租車在現(xiàn)代城市交通系統(tǒng)中起著舉足輕重的作用，為城市人民的生活出行帶來了極大的方便，出租車計費系統(tǒng)的穩(wěn)定、準確以及可靠直接關系到人民群眾的切身利益。因此設計一套計費準確可靠的計費系統(tǒng)顯得非常重要。 同時，本系統(tǒng)涉及的知識面比較廣，能夠鍛煉學生的各方面的專業(yè)知識，能夠使學生把理論知識與實踐相結合，對學生所學知識進行一次總結和審核。設計一個基于單片機的出租車計費系統(tǒng)可以利用 AT89C51 單片機作為中心處理單元，結合霍爾傳感器 A44E 來測量計算路程，以及使用數(shù)據(jù)掉電 保護芯片 AT24C02 來存儲數(shù)據(jù)。該出租車計費系統(tǒng)能夠實現(xiàn)數(shù)據(jù)的復位、白天 /晚上轉換、數(shù)據(jù)輸出、計時計價、單價輸出與調整、路程輸出、超速報警等功能。本設計不僅要完成計價器的基本功能，還能根據(jù)白天、黑夜、中途等待來調節(jié)單價。 關鍵詞 單片機； 霍爾傳感器； AT89C51； AT24C02 徐州工 程學院畢業(yè)設計（論文） II Abstract A taxi in modern urban transportation system plays an important role for the life of the urban people, brought great convenience to stable and accurate and reliable of the taximeter relates directly to the vital interests of the people. Therefore designing a set of accurate and reliable billing system bees very important. Meanwhile, the system involves wide knowledge, students can exercise every aspect of professional knowledge and enable students to put theory knowledge bining with is a summary and audit of knowledge for the students. Designing a taxi billing system based on SCM can use AT89C51 as the central processing unit,bining with sensor of pressureA44E to measure and calculate distances, and to use the data off electricity AT24C02 to store data protection chip. The taxi billing system can realize the data reduction, day/night translation, data output, timing valuation, unit price output and adjustment, journey output, speeding alarm functions. This design not only want to plete the basic function of the meter, can also according to the day and the night, midway waiting to adjust the price. Keywords SCM sensor of pressure AT89C51 AT24C02 徐州工 程學院畢業(yè)設計（論文） I 目 錄 1 緒論 ............................................................................................................................................. 1 系統(tǒng)研究背景 ........................................................................................................................ 1 系統(tǒng)研究意義 ....................................................................................................................... 1 本系統(tǒng)設計要求及指標 ........................................................................................................ 1 論文主要內容 ....................................................................................................................... 2 2 霍爾傳感器 ................................................................................................................................. 3 霍爾傳感器 A44E 結構及工作原理 .................................................................................... 3 霍爾傳感器 A44E 芯片的引腳及功能 ................................................................................ 4 脈沖計數(shù)法測速 ................................................................................................................... 4 3 系統(tǒng)硬件設計 ............................................................................................................................. 6 單片機簡介 ........................................................................................................................... 6 AT89C51 單片機簡介 ...................................................................................................... 7 AT89C51 單片機引腳介紹 .............................................................................................. 7 AT24C02 簡介 ........................................................................................................................ 9 管腳配置 ......................................................................................................................... 9 .......................................................................................................................... 9 功能描述 ....................................................................................................................... 10 ........................................................................................................................ 10 LCD1602 液晶顯示模塊 ..................................................................................................... 11 LCD1602 的結構及功能 ............................................................................................... 11 LCD1602 液晶顯示指令集 ........................................................................................... 12 系統(tǒng)硬件具體設計 ............................................................................................................. 13 霍爾傳感器電路設計 ................................................................................................... 13 LCD 顯示電路設計 ....................................................................................................... 13 AT24C02 掉電保護電路設計 ........................................................................................ 14 直流電機電路設計 ....................................................................................................... 14 鍵盤電路設計 ............................................................................................................... 15 4 系統(tǒng)軟件設計 ........................................................................................................................... 17 Keil C51 語言軟件開發(fā)系統(tǒng)簡介 ...................................................................................... 17 系統(tǒng)軟件具體設計 ............................................................................................................. 17 主程序設計 .................................................................................................................... 17 鍵盤服務程序 ............................................................................................................... 18 徐州工 程學院畢業(yè)設計（論文） II 顯示子程序服務程序 .......................................................................