單片機雙工通信時用到的校驗方式 Ø奇偶校驗原理:通過計算數據中“1”的個數是奇數還是偶數來判斷數據的正確性。在被校驗的數據后加一位校驗位或校驗字符用作校驗碼實現校驗。 Ø校驗位的生成方法 Ø奇校驗:確保整個被傳輸的數據中“1”的個數是奇數個,即載荷數據中“1”的個數是奇數個時校驗位填“0”,否則填“1”; 偶校驗:確保整個被傳輸的數據中“1”的個數是偶數個,即載荷數據中“1”的個數是奇數個時校驗位填“1”,否則填“0”
上傳時間: 2013-10-16
上傳用戶:天誠24
為提高電容測量精度,針對電容式傳感器的工作原理設計了基于PIC16LF874單片機電容測量模塊。簡單闡述了電容測量電路的應用背景和國內外研究現狀,介紹了美國Microchip公司PIC16LF874單片機的特性。電容式傳感器輸出的動態微弱電容信號通過PS021型電容數字轉換器把模擬量數據轉換成數字量數據,所測數據由PIC16LF874單片機應用程序進行處理、顯示和保存。實驗結果表明,固定電容標稱值為10~20 pF 的測量值相對誤差在1%以內,同時也可知被測電容容值越大,測量值和標稱值相對誤差越小。 Abstract: To improve the accuracy of capacitance measurement,aimed at the principle of work of mercury capacitance acceleration transducer,the design of micro capacitance measurement circuit is based on the key PIC16LF874 chip. Briefly discusses the application of the capacitance measuring circuit for the background and status of foreign researchers,focusing on the United States PIC16LF874 microcontroller features. Capacitive sensor outputed signal through the dynamics of weak PS021-chip capacitors (capacitancedigital converter) to convert analog data into digital data,the measured data from the PIC16LF874 microcontroller application process, display and preservation. Experimental results show that the fixed capacitor 10pF ~ 20pF nominal value of the measured value of relative error is within 1%,but also it canbe seen the value of the measured capacitance larger,measuring value and the nominal value of relative error smaller.
上傳時間: 2013-10-29
上傳用戶:wojiaohs
設計一種基于ATmega16L單片機的溫度控制系統,闡述該系統的軟硬件設計方案。采用模塊化設計方法,利用增量式PID算法使被控對象的溫度值趨于給定值。實驗結果表明該系統具有良好的檢測和控制功能。 Abstract: This paper designs a temperature control system based on ATmega16L,describes the hardware and software de-sign scheme of the system,adopts the modularized design method and utilizes the incremental PID algorithm to realize the temperature of controlled device incline to the given value.The experiment result indicates that the system has good detec-tion and control function
上傳時間: 2013-10-09
上傳用戶:stvnash
首先研究CAN總線和SAE J1939協議,提出一種基于MC9S12HZ256微控制器的總線式汽車數字儀表解決方案。詳細介紹SAE J1939協議的報文幀格式及應用層協議中發動機相關參數的定義,以及步進電機及其驅動和車速信號的處理方法。該數字儀表系統硬件平臺由微處理器和信號采集和信息處理及顯示等模塊組成。軟件設計部分編程實現了對CAN總線和各傳感器數據的讀取、處理。該系統能夠實時反映車輛工況。 Abstract: In this paper,CAN bus and SAE J1939protocol are researched,and a vehicle digital instrument solution based on MC9S12HZ256MCU is proposed.The message frame format and some engine-related parameters’definition in SAE J1939application layer protocol are introduced in detail.Stepper motor and its driver,the methods of speed signal process-ing are also introduced.The hardware platform of vehicle digital instrument is composed by MCU,signal acquisition mod-ule,and signal processing and displaying module.Data receiving and processing from CAN bus and sensors are accom-plished by programming,and vehicle condition can be reflected in real-time.
上傳時間: 2013-10-20
上傳用戶:huannan88
摘要:本文介紹應用PIC16C57單片機設計的一種可編程、高性能的數碼式樓宇對講系統,詳細闡明了有關工作原理和關鍵技術。本系統充分應用PIC單片機的軟硬件資源,具有可編程、電路簡單、功能強大等優點,在安居工程、樓宇技防系統等領域具有廣泛的應用前景。 關鍵詞:PIC 單片機 樓宇對講 編碼 譯碼 可編程
上傳時間: 2013-11-14
上傳用戶:hj_18
針對材料試驗機等設備中要求測量或控制材料拉伸或壓縮的位移,一般采用光電軸角編碼器檢測位置信號,輸出正交編碼脈沖信號。若采用其他方法檢測位置信號,必然導致電路設計復雜,可靠性降低。因此,提出一種基于LS7266R1的電子式萬能材料試驗機設計方案。給出了試驗機中的控制器工作原理,LS7266R1與單片機的接口硬件設計,以及主程序軟件流程圖。巧妙地把力量傳感器,位移傳感器等機械運動狀態的壓力或拉力以及位置坐標,變成了電壓信號和電脈沖數字信號,供A/D測量和LS7266R1計數,從而實現了獨立完成材料試驗控制或通過PC機串口命令完成材料試驗控制。 Abstract: Aiming at the requirement that the displacement of the tension and compression always be tested and controlled in the equipement such as material testing machine. The position signal was tested by photoelectric axial angle coder. Therefore, the paper proposes the design of electronic universal testing machine design based on LS7266R1. If the position signal detected by other methods, will inevitably lead to the circuit design complexity, reliability decreased. The work theory of the controller, the hardware interface design between LS7266R1 and single chip, and the flow chart of main program, are presented in this paper. The signal of the compression or tension power and displacement at working, which tested by power sensor and displacement sensor especially, is changed into electric voltage and electric pulse numerical signals. And these signals can be tested by A/D and counted by LS7266R1. Finally the test of the material properties can be controlled by itself, or controlled by the COM command of PC.
上傳時間: 2013-11-02
上傳用戶:yl1140vista
設計實現了一種基于MSP430系列超低功耗單片機的新型高精度自控式骨矯形器,介紹了系統的總體設計及硬件軟件設計。試驗表明,該骨矯形器可實現自控內固定、牽張、回縮及加壓固定功能,且功耗低、操控簡單、控制精度高、安全可靠。
上傳時間: 2013-10-16
上傳用戶:1427796291
介紹了一款可以同時讀寫接觸式卡和非接觸式卡的多功能讀卡器,詳細闡述了射頻芯片PN532和主控芯片ST2211的外圍硬件電路和整個讀卡器的軟件構架。同時對讀卡器電源管理、低功耗設計、多通信方式融合等進行了較詳細的分析
上傳時間: 2013-10-23
上傳用戶:chongchongsunnan
摘要:研究了用單片機控制的單相后備式方波輸出UPS的控制技術及實現,分析了系統的工作原理,給出了硬件實現電路和算法框圖,并測出了市電逆變相互轉換等主要實驗結果。關鍵詞:不間斷電源;單片機;推挽變換器
上傳時間: 2013-10-28
上傳用戶:1051290259
摘要:本文針對單片機課程在高職院校中普遍存在上課難的問題,提出以實踐為主,采用實驗任務指派,教師在課堂中啟發式的教學方法。教學實踐證明這種方法起到了積極的推動作用,學生能夠從中掌握實用技能,為日后就業打下堅實基礎。關鍵詞:任務式;啟發式;教學改革
上傳時間: 2013-11-30
上傳用戶:oooool