【正文】 il 作為編程軟件，軟件設(shè)計(jì)部分實(shí)現(xiàn)了將溫度傳感器采集的 數(shù)字 信號(hào) 以十進(jìn)制 的 形式表示 ，并在 LCD1602 上 給予 準(zhǔn)確顯示，當(dāng)溫度值超過(guò)標(biāo)準(zhǔn)體溫值（設(shè)定值）時(shí)蜂鳴器報(bào)警，測(cè)定溫度 用按鍵予以保持 。 測(cè)量時(shí)間短， 單次測(cè)量反應(yīng)時(shí)間不到一秒鐘。 關(guān)鍵字 ： 數(shù)字體溫計(jì) ， 51 單片機(jī) ， DS18B20， LCD1602 II Abstract Through the paper, I researched the principle and achievement of the digital thermometer, which is based on Singlechip microputer. The design is divided into two parts: the hardware part and the software part, the hardware part is divided into data collection part, displaying part, keying and alerting part, while realizes the design of the whole circuitry, the data acquisition and the synthesized of the display part. The central processing chip is 51 Singlechip microputer, the temperature sensor is DS18B20 and the displayer is LCD1602. The software design part uses C language to programme, uses keil as the programme software, the software design part realizes turning the signal temperature sensor collects to decimal system, displaying the temperature on LCD1602, when the temperature is higher than the standard temperature (set value), the buzzer give an alarm, the key is used to keep the measured temperature. Compared the digital thermometer with the traditional thermometer, the digital thermometer based on Singlechip which is cheap can measure temperature accuracily. The accuracy is . It can display the number at one radix point. The measuring time is short, the time measure each time is shorter than one second. It can be carried conveniency, it is cheap and it is accurate. Key words: Digital Thermometer， 51 Singlechip Microputer， DS18B20， LCD1602 III 目 錄 前 言 .......................................................................................................................................... 1 1 系統(tǒng)方案設(shè)計(jì) ........................................................................................................................ 2 總體方案設(shè)計(jì) .................................................................................................................. 2 總體結(jié)構(gòu)框圖 .................................................................................................................. 3 2 設(shè)計(jì)原理 ................................................................................................................................ 4 單片機(jī) AT89C51 ............................................................................................................. 4 單片機(jī)簡(jiǎn)介 ............................................................................................................... 4 AT89C51..................................................................................................................... 4 AT89C51 閑散節(jié)電模式 ............................................................................................ 7 AT89C51 掉電模式 .................................................................................................... 7 溫度傳感器 DS18B20 ..................................................................................................... 8 DS18B20 性能 ........................................................................................................... 8 DS18B20 的外形和內(nèi)部結(jié)構(gòu) ................................................................................... 8 相關(guān)數(shù)據(jù) ................................................................................................................... 9 DS18B20 寄存器配置 ............................................................................................. 10 高速暫存存儲(chǔ)器 ..................................................................................................... 10 DS18B20 使用中注意事項(xiàng) ..................................................................................... 12 液晶屏 LCD1602 ........................................................................................................... 13 液晶顯示簡(jiǎn)介 ......................................................................................................... 13 LCD1602 的基本參數(shù)及引腳功能 ......................................................................... 14 LCD1602 的指令說(shuō)明及時(shí)序 ................................................................................. 15 3 系統(tǒng)硬件設(shè)計(jì) ...................................................................................................................... 18 硬件總體設(shè)計(jì)思路 ........................................................................................................ 18 單片機(jī)時(shí)鐘電路與復(fù)位電路設(shè)計(jì) ................................................................................ 19 時(shí)鐘電路設(shè)計(jì) ......................................................................................................... 19 復(fù)位電路設(shè)計(jì) ......................................................................................................... 19 溫度傳感模塊設(shè)計(jì) ........................................................................................................ 19 顯示模塊設(shè)計(jì) ................................................................................................................ 20 4 系統(tǒng)軟件設(shè)計(jì) ...................................................................................................................... 22 軟件流程圖 .................................................................................................................... 22 溫度檢測(cè)模塊 ................................................................................................................ 22 顯示模塊 ........................................................................................................................ 24 LCD1602 初始化 ..................................................................................................... 24 寫(xiě)指令及寫(xiě)數(shù)據(jù) ..................................................................................................... 24 程序代碼 .......................................................................................