【正文】 d,0xfd, 0x87,0xff,0xef}。常用 LED 數(shù)碼管顯示的數(shù)字和字符是 0、 A、 B、 C、 D、 E、 F。封裝后的 DS18B20可用于電纜溝測(cè)溫，高爐水循環(huán)測(cè)溫，鍋爐測(cè)溫，機(jī)房測(cè)溫，農(nóng)業(yè)大棚測(cè)溫，潔凈室測(cè)溫，彈藥庫(kù)測(cè)溫等各種非極限溫度場(chǎng)合。同時(shí)采用 PWM 脈寬調(diào)制方式改變之流風(fēng)扇電機(jī)的轉(zhuǎn)速。 demands. Wherein the elements for automatic control system has many kinds, but particularly the microcontroller, PLC, puter, etc. has a pivotal position in the industrial production. In this paper, microcontroller, for example, the temperature sensor is a detailed description of how the microcontroller to control the speed of the motor. Such examples may seem very simple, but in real life production plays an important role in it. For example, notebook cooling systems, intelligent fans, there are some serious heat large machinery, etc. Such programs are mostly used to control the body39。 近幾年來(lái)微 型機(jī)快速發(fā)展，國(guó)外交直流系統(tǒng)數(shù)字化已經(jīng)達(dá)到實(shí)用階段由于以微處理器為核心的數(shù)字控制系統(tǒng)硬件電路的標(biāo)準(zhǔn)化程度高，制作成本低，且不受器件溫 度漂 移的 影 響，其 中單 片機(jī) 最 受歡迎 。單 片機(jī) （ Single chip microputer） 微 型 計(jì) 算 機(jī) 簡(jiǎn) 稱(chēng) 單 片 機(jī) ， 是 典 型 的 嵌 入 式 微控制器（ Microcontroller Unit），常用英文字母的縮寫(xiě) MCU 表示單片機(jī)，單片機(jī)又稱(chēng)單片微控制器 ，它不是完成某一個(gè)邏輯功能的 芯片 ，而是把一個(gè) 計(jì)算機(jī)系統(tǒng)集成到一個(gè)芯片上。s internal heat, thus ensuring the normal operation of the work. In recent years, the rapid development of microputers, foreign Digital ACDC system has reached the practical stage due to the high degree of standardization of microprocessor core digital control system hardware circuit, low production costs, and the device is not affected by temperature drift, which SCM the most popular. SCM (Single chip microputer) singlechip microputers referred to, is a typical embedded microcontroller (Microcontroller Unit), monly used abbreviations in alphabetical said MCU MCU, microcontroller, also known as singlechip microcontroller, it is not pleted a certain logic chips , but to a puter system integrated into a chip. SCM consists of puting, controller, memory, input and output devices, the equivalent of a miniputer (minimum system), and a puter pared to the lack of a singlechip peripherals. Speaking in general terms: a chip has bee a puter. Its small size, light weight, cheap, learning, application and development of facilities provided. At the same time, learning to use a puter microcontroller is the best choice to understand the principle and structure. It was first to be used in industrial control. Temperature sensor from the early 17th century, people began to take advantage of the temperature measurement. In support of semiconductor technologies, this century have developed a semiconductor thermocouple sensor, PN junction temperature sensor and integrated temperature sensor. Correspondingly, based on the interaction of waves with matter of law, have developed acoustic temperature sensors, infrared sensors and microwave sensors. Temperature sensors are a variety of sensors in a wide variety of the most monly used, modern appearance temperature sensor was very small, so it is more widely used in various fields of production practices, but also for people39。并通過(guò)兩個(gè)按鍵改變預(yù)設(shè)溫度的大小，一個(gè)提高預(yù)設(shè)溫度，另一個(gè)降低預(yù)設(shè)溫度。耐磨耐碰，體積小，使用方便，封裝形式多樣，適用于各種狹小空間設(shè)備數(shù)字測(cè)溫和控制領(lǐng)域 。 其硬件接線(xiàn)圖如下： 第 6 頁(yè) 第四章 電路的設(shè)計(jì) 開(kāi)關(guān)復(fù)位與晶振電路 : 在單片機(jī)系統(tǒng)中，處于單片機(jī)本身需要復(fù)位意外，外部擴(kuò)展 I/O 端口電路同樣需要復(fù)位，因此需要一個(gè)包括上電按鈕復(fù)位在內(nèi)的系統(tǒng)同步復(fù)位電路。 uchar dispbitcode[]={ 0xfe,0xfd,0xfb,0xf7, 0xef,0xdf,0xbf,0x7f}。 P2=0xff。