Handheld electronic devices play a key role in our everydaylives. Because dependability is paramount, handhelds arecarefully engineered with lightweight power sources forreliable use under normal conditions. But no amount ofcareful engineering can prevent the mistreatment theywill undergo at the hands of humans. For example, whathappens when a factory worker drops a bar code scanner,causing the battery to pop out? Such events areelectronically unpredictable, and important data storedin volatile memory would be lost without some form ofsafety net—namely a short-term power holdup systemthat stores suffi cient energy to supply standby power untilthe battery can be replaced or the data can be stored inpermanent memory.
標(biāo)簽： 超級(jí)電容器 備用電源 手持設(shè)備
上傳時(shí)間： 2013-11-05
上傳用戶：coeus
Abstract: This application note describes how to build, debug, and run applications on the on-board MAXQ622microcontroller to interface with the DS8005 dual smart card interface. This is demonstrated in both IAREmbedded Workbench and the Rowley CrossWorks IDE, using sample code provided with the kit.
標(biāo)簽： 8005 DS 評(píng)估套件
上傳時(shí)間： 2013-10-29
上傳用戶：ddddddd
在理論分析循環(huán)碼編碼和譯碼基本原理的基礎(chǔ)上，提出了基于單片機(jī)系統(tǒng)的(24，16)循環(huán)碼軟件實(shí)現(xiàn)編碼、譯碼的方案。仿真結(jié)果表明(24，16)循環(huán)碼能有效地克服來(lái)自通訊信道的干擾，保證數(shù)據(jù)通信的可靠及系統(tǒng)的穩(wěn)定，使誤碼率大幅度降低。本論文對(duì)(24，16)循環(huán)碼的研究結(jié)果表明，可以有效地降低錯(cuò)誤概率和提高系統(tǒng)的吞吐量，實(shí)現(xiàn)糾錯(cuò)僅需要在接收端增加有限的存儲(chǔ)空間和計(jì)算復(fù)雜度，具有一定的實(shí)用價(jià)值。 Abstract: Based on analyzing the theory of encoding and decoding of cyclic code， this paper showed the schemes of encoding and decoding of(24，16)cyclic code by the software and based on microcontroller. Simulation results show that using (24，16) cyclic codes can effectively overcome the interference from communication channel， ensure the reliability and stability of data communication systems， and reduce the bit error rate greatly. The results of this paper show that by using the (24，16) cyclic code， the error rate can be reduced and the system throughput can be improved. Meanwhile， the system only needs to enlarge limited storage space and computation the complexity at the receiving end to realize error correction. Thus the (24，16) cyclic code has a practical value.
標(biāo)簽： 24 16 單片機(jī)系統(tǒng) 循環(huán)碼
上傳時(shí)間： 2013-11-09
上傳用戶：gaoliangncepu
Designing Boards with Atmel AT89C51,AT89C52, AT89C1051, and AT89C2051 for Writing Flash at In-Circuit Test. Recent improvements in chips and testers have made it possible for the tester to begin taking over the role tradi-tionally assigned to the PROM program-mer. Instead of having a PROM pro- grammer write nonvolatile memories before assembling the board, the in-cir- cuit tester writes them during in-circuit testing operations. Many Teradyne Z18- series testers are now in use loading code into nonvolatile memories, micro- controllers and in-circuit programmable logic devices. The purpose of this note is to explain how the Z18 approaches the writing task for Atmel AT89C series IC’s, so that designers of boards using these chips can get the best results.
上傳時(shí)間： 2013-11-17
上傳用戶：xiaozhiqban
針對(duì)目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機(jī)啟動(dòng)時(shí)不能設(shè)置BIOS，提出一種PS2鍵盤的設(shè)計(jì)方法。基于W78E052D單片機(jī)，采用8通道串行A/D轉(zhuǎn)換器設(shè)計(jì)了8個(gè)TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發(fā)送，正交編碼器信號(hào)通過(guò)XC9536XL轉(zhuǎn)換為單片機(jī)可接收的中斷信號(hào)，軟件接收到中斷信息后等效處理成按鍵。結(jié)果表明，在滿足開(kāi)機(jī)可設(shè)置BIOS同時(shí)，又可實(shí)現(xiàn)超聲特有功能，不需要專門設(shè)計(jì)驅(qū)動(dòng)程序，接口簡(jiǎn)單，成本低。 Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
標(biāo)簽： 單片機(jī) B超 數(shù)字化 鍵盤設(shè)計(jì)
上傳時(shí)間： 2013-10-10
上傳用戶：asdfasdfd
在深入了解Flash存儲(chǔ)器的基礎(chǔ)上，采用單片機(jī)自動(dòng)檢測(cè)存儲(chǔ)器無(wú)效塊。主要通過(guò)讀取每一塊的第1、第2頁(yè)內(nèi)容，判斷該塊的好壞，并給出具體的實(shí)現(xiàn)過(guò)程，以及部分關(guān)鍵的電路原理圖和C語(yǔ)言程序代碼。該設(shè)計(jì)最終實(shí)現(xiàn)單片機(jī)自動(dòng)檢測(cè)Flash壞塊的功能，并通過(guò)讀取ID號(hào)檢測(cè)Flash的性能，同時(shí)該設(shè)計(jì)能夠存儲(chǔ)和讀取1GB數(shù)據(jù)。 Abstract: On the basis of in-depth understanding the Flash chips，this paper designs a new program which using the SCM to detect the invalid block.Mainly through reading the data of the first and second page to detect the invalid block.Specific implementation procedure was given,and the key circuit schematic diagram and C language program code was introduced.This design achieved the function of using the MCU checks the invalid block finally，and increased the function by reading the ID number of Flash to get the performance of the memory.And the design also can write and read1GB data
標(biāo)簽： Flash 單片機(jī) 存儲(chǔ)器 自動(dòng)檢測(cè)
上傳時(shí)間： 2013-10-25
上傳用戶：taozhihua1314
應(yīng)用德國(guó)Micronas公司的CDC3207G微控制器開(kāi)發(fā)了一款汽車儀表板系統(tǒng)。詳細(xì)地介紹了該系統(tǒng)的硬件原理，以及步進(jìn)電機(jī)，音頻控制，LCD顯示，LED指示燈和報(bào)警燈等幾個(gè)模塊的實(shí)現(xiàn)方法。應(yīng)用μC/OS-II實(shí)時(shí)操作系統(tǒng)開(kāi)發(fā)軟件。著重介紹了啟動(dòng)代碼的設(shè)計(jì)和任務(wù)的規(guī)劃。 Abstract: A dashboard system is developed by using CDC3207G microcontroller made by Micronas.The hardware of the sys-tem and the realization of the step motor module,audio module,LCD display and LED indicator and alarm module are ex-plained in detail.The μC/OS-II real-time operating system is used for the software development and the starting code design and the task planning is explained specifically.
標(biāo)簽： 3207G 3207 CDC 汽車儀表板
上傳時(shí)間： 2013-10-26
上傳用戶：x4587
在介紹基于MSP430單片機(jī)的指紋保險(xiǎn)柜工作原理的基礎(chǔ)上，從系統(tǒng)軟件設(shè)計(jì)的角度出發(fā)，詳細(xì)介紹了指紋保險(xiǎn)柜軟件的總體分析過(guò)程、程序結(jié)構(gòu)的設(shè)計(jì)以及代碼的編寫，給出了按鍵管理流程和部分源代碼。 Abstract: On basis of the operating principle of MSP430 microcontroller-based fingerprint safe,the general analyzing process,program designing and code compiling of the fingerprint safe software are introduced mainly,and the key-press flows chart and some codes according to the system software designing are put forward.
上傳時(shí)間： 2014-12-27
上傳用戶：gaojiao1999
利用Atmel公司的ATmega168微處理器，采用A/D轉(zhuǎn)換方式來(lái)實(shí)現(xiàn)按摩椅控制器的鍵盤接口，通過(guò)在硬件電路中巧妙地選擇電阻，在軟件設(shè)計(jì)中采用數(shù)字濾波、二分法和區(qū)間鑒定等方法，靈敏可靠地實(shí)現(xiàn)了按摩椅中30個(gè)按鍵的處理。給出了硬件電路設(shè)計(jì)和軟件設(shè)計(jì)思想以及部分匯編代碼。 Abstract: This paper chooses A/D conversion method to realize the keyboard interface of the controller by using ATmega168 microchip from Atmel Company.It accomplishes 30-key dealing sensitively and reliably in massage chair through skillfully selecting resistors in hardware circuit and using digital filter,dichotomy and area-judging method in software design.The hardware design circuit, software design idea and partly assembles code are presented mainly.
上傳時(shí)間： 2014-01-10
上傳用戶：咔樂(lè)塢
在需要實(shí)時(shí)大量輸入漢字的顯示控制處理應(yīng)用中，利用傳統(tǒng)單片機(jī)實(shí)現(xiàn)顯示控制的設(shè)計(jì)方法是較難實(shí)現(xiàn)的。帶漢字字庫(kù)的液晶模塊的使用使得小容量ROM單片機(jī)的大量漢字信息輸入與顯示成為可能。提出了針對(duì)漢字字庫(kù)編碼的二級(jí)索引拼音輸入檢索方法,介紹了以ST7920作為控制器的帶漢字字庫(kù)的液晶顯示模塊的接口方法及漢字顯示和控制原理，給出了通用計(jì)算機(jī)鍵盤在單片機(jī)中的串行接口，采用該技術(shù)可大大增強(qiáng)單片機(jī)的漢字輸入功能。為小容量ROM單片機(jī)的大批量漢字信息處理提供了一種漢字輸入解決方案。 Abstract: It is difficult to realize Chinese characters input method based on the embedded system by using the traditional design method of display control. It is possible to input and display Chinese characters based on the embedded system with the ROM of small content by using the LCD module with Chinese characters.Chinese characters input method of the quadric index recall in allusion to Chinese characters code is brought forward.The interface and the principle of Chinese characters display control based on the LCD module controlled with the ST7920 is introduced too.The serial interface of the computer keyboard in common use and the embedded system is given at the same time. It can enhance the embedded system function of Chinese characters input by using this technology, and provide a kind of Chinese characters input scheme for the embedded system with small capacity ROM.
上傳時(shí)間： 2013-11-19
上傳用戶：jhksyghr
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