便攜式信號(hào)采集在機(jī)器健康診斷系統(tǒng)中有較高的應(yīng)用價(jià)值。機(jī)器健康診斷的信號(hào)特點(diǎn)是包括低頻信號(hào)。本文研究是為了實(shí)現(xiàn)簡(jiǎn)易而且低成本的低頻便攜式信號(hào)采集。以Microchip公司單片機(jī)PIC18F1320為核心設(shè)計(jì)信號(hào)采集電路，實(shí)現(xiàn)了信號(hào)的采集和保存。系統(tǒng)采用串行電可擦除芯片24LC32A保存數(shù)據(jù)，經(jīng)過(guò)有線(xiàn)通信，信號(hào)數(shù)據(jù)由串行口通過(guò)MAX232芯片輸送到微型計(jì)算機(jī)接收和保存，最后繪制出信號(hào)波形。 微型計(jì)算機(jī)程序采用Visual Basic編程。研究成功采樣頻率為3 kHz的復(fù)雜信號(hào)，證明該方案符合設(shè)計(jì)要求。 Abstract: Portable signal acquisition is useful in machine health monitoring systems. The signal characteristics of machine health monitoring includes low frequency signals. The goal of this study is to realize simple, inexpensive and portable low frequency signal sampling. This paper provides the project of signal acquisition system design based on PIC18F1320 microcontroller manufactured by the Microchip Technology Incorporation to achieve signal sampling and storage. The system adopted EEPROM 24LC32A to store the signal data. The microcomputer received data via wired link with the MAX232 IC through the serial port. The microcomputer program, programmed in Visual Basic, received the data, stored it and plotted the signal. The study successfully samples 3kHz complicated signals and thus meets the design requirement.
上傳時(shí)間： 2013-11-19
上傳用戶(hù)：moerwang
為解決電致變色器件的顏色變化受外界環(huán)境顏色控制的問(wèn)題，設(shè)計(jì)了一種基于單片機(jī)的便攜式顏色自適應(yīng)識(shí)別電路。與傳統(tǒng)顏色識(shí)別電路相比較，該電路利用數(shù)字式的顏色傳感器來(lái)獲取外界環(huán)境顏色，產(chǎn)生的數(shù)字顏色信號(hào)易于單片機(jī)進(jìn)行處理。在電路中，下位機(jī)部分主要負(fù)責(zé)獲取電致變色器件變色參數(shù)及控制電致變色器件的顏色變化;而上位機(jī)部分主要負(fù)責(zé)把下位機(jī)獲取的電致變色器件變色參數(shù)進(jìn)行電壓到顏色的曲線(xiàn)擬合，并通過(guò)藍(lán)牙通信把擬合曲線(xiàn)參數(shù)傳遞給下位機(jī)。結(jié)果表明，該電路能自動(dòng)根據(jù)環(huán)境顏色提供-4~4 V范圍步進(jìn)為0.1 V的電壓來(lái)驅(qū)動(dòng)電致變色器件的顏色顯示，與傳統(tǒng)的顏色識(shí)別電路設(shè)計(jì)相比，識(shí)別的精度和速度都得到了明顯改善。 Abstract: In this paper， a portable adaptive circuit for color identification(PACCI) based on MCU was designed. Compared to the traditional color identification circuit， the PACCI adopts digital sensor to detect the color data from external environment and further generate digital color data， which can be processed easily by MCU. In PACCI， the slave is mainly responsible for detecting the color parameters of the corresponding elcreochromic device and further driving it. For the master， which is mainly responsible for the color curve fitting based on the parameters of the electrochromic device， and transmits the fitting parameters to the slave through the bluetooth device. The results show that the PACCI can provide the basis voltage range from -4V to 4V automatically based on the colors of external environment with step as 0.1V to drive the corresponding electrochromic device. Compared to the traditional color recognition circuit， the recognition accuracy and speed of PACCI have been improved significantly.
上傳時(shí)間： 2013-11-09
上傳用戶(hù)：franktu
現(xiàn)有基于MAX7219芯片的數(shù)碼管驅(qū)動(dòng)電路只適用于小尺寸LED，為擴(kuò)展其使用范圍，在介紹動(dòng)態(tài)顯示芯片MAX7219功能的基礎(chǔ)上，提出了一個(gè)基于該芯片的8位高亮度8英寸數(shù)碼管驅(qū)動(dòng)電路。電路保留了MAX7219芯片的功能強(qiáng)大、編程簡(jiǎn)單等優(yōu)點(diǎn)，通過(guò)74LS273鎖存器和ULN2803達(dá)林頓驅(qū)動(dòng)器，實(shí)現(xiàn)了對(duì)任意大尺寸數(shù)碼管提供較高電壓和電流驅(qū)動(dòng)的靜態(tài)顯示，并亮度可調(diào)。 Abstract: The existing display-driving circuit based on MAX7219 was only applicable to small-size LED. To expand its use, based on the function introduction of dynamic display chip MAX7219, a display-driving circuit for high-brightness 8-bit LED with the size of 8-inch was proposed. The advantages of MAX7219 were retained, such as powerful function and simple programming. Static display with adjustable brightness for large-size LED with higher voltage and current was achieved with the help of 74LS273 and ULN2803.
標(biāo)簽： 7219 MAX LED 數(shù)碼顯示
上傳時(shí)間： 2013-10-23
上傳用戶(hù)：31633073
設(shè)計(jì)了一種基于PIC16C71單片機(jī)的數(shù)字水溫配制閥。該配制閥采用NTC熱敏電阻作溫度傳感器，與固定電阻組成簡(jiǎn)單分壓電路作為水溫測(cè)量電路，利用PIC16C71單片機(jī)內(nèi)置的8位A/D轉(zhuǎn)換器把熱敏電阻上的模擬電壓轉(zhuǎn)換為數(shù)字量，PIC16C71單片機(jī)控制直流電機(jī)驅(qū)動(dòng)混水閥調(diào)節(jié)冷熱水的混合比例實(shí)現(xiàn)水溫調(diào)節(jié)。給出了控制電路圖，對(duì)水溫測(cè)量電路的參數(shù)選擇和測(cè)溫精度作了詳細(xì)討論。實(shí)驗(yàn)和分析表明，選用阻值較大的NTC熱敏電阻和分壓電阻可較好地解決熱敏電阻因功耗較大造成的熱擊穿問(wèn)題。 Abstract: A digital valve for controlling water temperature based on PIC16C71 was presented in this paper.A bleeder circuit which consisted of a NTC thermistor as temperature sensor and a fixed resistance was designed as water temperature measuring circuit.The analog voltage on the thermistor was converted into digital signal by a 8-bit A/D converter embedded in PIC16C71. Based on the digital signal， the MCU PIC16C71 drived the valve by a DC motor to adjust the water temperature through adjusting the proportion of hot water and cold water.The circuit diagram of controller was given，the principle，the component parameters and the accuracy of measuring temperatures were also dissertated in detail. It was found by experiment and analysis that thermal breakdown of thermistor caused by high power could be solved by selecting thermistor and fixed resistance with high impedance value.
上傳時(shí)間： 2013-11-08
上傳用戶(hù)：Yue Zhong
針對(duì)目前使用的RS232接口數(shù)字化B超鍵盤(pán)存在PC主機(jī)啟動(dòng)時(shí)不能設(shè)置BIOS，提出一種PS2鍵盤(pán)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(pán)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(mǎn)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(zhuān)門(mén)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(pán)設(shè)計(jì)
上傳時(shí)間： 2013-10-10
上傳用戶(hù)：asdfasdfd
在航電系統(tǒng)維護(hù)過(guò)程中，為解決定位故障的效率和降低維修成本等問(wèn)題，提出了基于ICD（Interface Control Document，接口控制文件）的1553B總線(xiàn)的信息監(jiān)控系統(tǒng)模型。該系統(tǒng)運(yùn)用數(shù)據(jù)采集卡對(duì)總線(xiàn)中傳輸?shù)男盘?hào)有無(wú)失真、偏差等電氣特性進(jìn)行檢測(cè)，并使用1553B通訊卡通過(guò)測(cè)控軟件LabWindows/CVI編程與ICD數(shù)據(jù)庫(kù)的動(dòng)態(tài)鏈接，實(shí)現(xiàn)總線(xiàn)信息的解析和故障的判斷。與傳統(tǒng)的維護(hù)過(guò)程相比，這種模型能夠從信號(hào)的電氣特性以及信息的解析等全方位的去檢測(cè)判斷故障的來(lái)源，并且能夠廣泛在其他1553B總線(xiàn)系統(tǒng)內(nèi)擴(kuò)展應(yīng)用。驗(yàn)證表明該監(jiān)控系統(tǒng)可以對(duì)總線(xiàn)信息進(jìn)行快速有效地監(jiān)測(cè)分析，能滿(mǎn)足應(yīng)用需求。 Abstract: In the process of avionics system maintenance， to solve the problems such as improving the efficiency of fast orientation to troubles and reducing maintenance cost， system of 1553B bus information monitor model based on ICD was proposed. The system observed whether the data which transmitted on the bus appear distortion and deviation by using data acquisition card. And using 1553B communication card programming of the measure software LabWindows/CVI and the dynamic linking of ICD database， message analysis and fault estimation could be realized. Compared with traditional maintenance， this model can all-dimensionally detect and analyze the source of faults from both electrical characteristics of the signal and message analysis， and it can be widely applied in the other 1553B system. Experiment shown that this monitor system can effectively detect and analyze the bus message and can meet the application requirements.
標(biāo)簽： 1553B 總線(xiàn) 信息監(jiān)控
上傳時(shí)間： 2013-11-23
上傳用戶(hù)：18752787361
摘要 本研究計(jì)劃之目的，在整合應(yīng)用以ARM為基礎(chǔ)的嵌入式多媒體實(shí)時(shí)操作系統(tǒng)于H.264/MPEG-4多媒體上。由于H.264是一種因應(yīng)實(shí)時(shí)系統(tǒng)(RTOS)所設(shè)計(jì)的可擴(kuò)展性串流傳輸(scalability stream media communication)的編碼技術(shù)。H.264主要架構(gòu)于細(xì)細(xì)粒可擴(kuò)展(Fine Granula Scalability,FGS)的壓縮編碼機(jī)制。細(xì)粒度可擴(kuò)展壓縮編碼技術(shù)是最新MPEG-4串流式傳輸標(biāo)準(zhǔn)，能依頻寛的差異來(lái)調(diào)整傳輸?shù)姆绞健＜?xì)粒度擴(kuò)展縮編碼技術(shù)以編入可選擇性的增強(qiáng)層(enhanced layers)于碼中，來(lái)提高影像傳輸?shù)馁|(zhì)量。本計(jì)劃主要在于設(shè)計(jì)一種簡(jiǎn)單有效的實(shí)時(shí)階層可擴(kuò)展的影像傳輸系統(tǒng)。在增強(qiáng)層編碼及H.264的基本層(base layer)編碼上使用漸進(jìn)的細(xì)粒度可擴(kuò)展編碼(Progressive Fine Granularity Scalable,PFGS)能直接使用H.264的格式特色來(lái)實(shí)現(xiàn)FGS。同時(shí)加入了LB-LLF(Layer-Based Least-Laxity-Fir stscheduling algorithm)的排程算法，來(lái)增 進(jìn)網(wǎng)路傳輸影像的質(zhì)量。由實(shí)驗(yàn)結(jié)果顯示本系統(tǒng)在串流影像質(zhì)量PSNR值上確有較佳的效能。
標(biāo)簽： 芯片系統(tǒng) 架構(gòu) 開(kāi)發(fā)平臺(tái)
上傳時(shí)間： 2014-12-26
上傳用戶(hù)：mpquest
提出了一種以S3C2440A為核心處理器的銀行評(píng)價(jià)器的設(shè)計(jì)方案，并結(jié)合XILINX公司的XL95144XL型CPLD，輔助S3C2440A，實(shí)現(xiàn)該銀行評(píng)價(jià)器的各部分功能以及系統(tǒng)信號(hào)之間的相互協(xié)調(diào)。該評(píng)價(jià)器在系統(tǒng)設(shè)計(jì)上采用液晶屏顯示，代替了以往簡(jiǎn)單的數(shù)碼管電路的顯示模式，在視覺(jué)上給人以全新的享受。同時(shí)，評(píng)價(jià)器增加了新的網(wǎng)絡(luò)供電方式，只要將評(píng)價(jià)器連接上網(wǎng)絡(luò)就可以正常工作，方便了客戶(hù)的使用。總之，此款銀行評(píng)價(jià)器采用了嵌入式系統(tǒng)的設(shè)計(jì)方案，大大豐富了系統(tǒng)功能，實(shí)現(xiàn)一個(gè)銀行評(píng)價(jià)器設(shè)計(jì)的新突破。 Abstract: S3C2440A of SamSung company is the core component of the embedded system. A design of bank assessor based on S3C2440A was provided in this paper. It used XL95144XL combined with S3C2440A to realize all the functions and coordination with system signals. This bank assessor used LCD to display instead of the former simple digital display and provided a new seusuous enjoment. Meanwhile，it provided a new method of network power supply，that the bank assessor could regularly work once it connected to the network，which is convenient for customers to use. In a word，this assessor takes embedded system，enriches the system’s functions and reclizes a new breakout.
標(biāo)簽： S3C2440A
上傳時(shí)間： 2013-11-03
上傳用戶(hù)：taa123456
為提高電容測(cè)量精度，針對(duì)電容式傳感器的工作原理設(shè)計(jì)了基于PIC16LF874單片機(jī)電容測(cè)量模塊。簡(jiǎn)單闡述了電容測(cè)量電路的應(yīng)用背景和國(guó)內(nèi)外研究現(xiàn)狀，介紹了美國(guó)Microchip公司PIC16LF874單片機(jī)的特性。電容式傳感器輸出的動(dòng)態(tài)微弱電容信號(hào)通過(guò)PS021型電容數(shù)字轉(zhuǎn)換器把模擬量數(shù)據(jù)轉(zhuǎn)換成數(shù)字量數(shù)據(jù)，所測(cè)數(shù)據(jù)由PIC16LF874單片機(jī)應(yīng)用程序進(jìn)行處理、顯示和保存。實(shí)驗(yàn)結(jié)果表明，固定電容標(biāo)稱(chēng)值為10~20 pF 的測(cè)量值相對(duì)誤差在1%以?xún)?nèi)，同時(shí)也可知被測(cè)電容容值越大，測(cè)量值和標(biāo)稱(chēng)值相對(duì)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(shí)間： 2013-10-29
上傳用戶(hù)：wojiaohs
生活中許多目標(biāo)的高度和水平距離需要進(jìn)行測(cè)量。目前主要的測(cè)量方法，仍以傳統(tǒng)的皮尺丈量為主，測(cè)量效率不高，有時(shí)還很不方便，沒(méi)有技術(shù)成熟的數(shù)字式測(cè)高測(cè)距產(chǎn)品。以基本的數(shù)學(xué)方法為理論依據(jù)，利用遙控小車(chē)做為載體，采用角度傳感器測(cè)量角度、霍爾傳感器測(cè)量水平距離等，通過(guò)單片機(jī)LM3S615進(jìn)行數(shù)據(jù)計(jì)算，實(shí)現(xiàn)了對(duì)待測(cè)目標(biāo)物體的高度、水平距離等數(shù)據(jù)的快速、精確和數(shù)字式的測(cè)量，高度測(cè)量精度可達(dá)99.06%，水平測(cè)量精度則可達(dá)98.06%。 Abstract: In our lives， the height and horizontal distance of some goals are needed to be measured. Because the currently used methods are still traditional tape-based measuring methods， and the measuring efficiency is low and inconvenient so some kinds of digital and portable measuring methods or instruments are needed. Based on the basic math theory， this paper designed and manufactured a portable， digital and remote controlled measuring mobile small vehicle， which assembled with angle measuring sensor for angle measurement and Hall sensor for horizontal distance measuring. MCU LM3S615 calculated the height and horizontal distance data gotten from these sensors. The measuring process is simple， the measuring results are more accurate and the measuring efficiency is higher than traditional measure instruments. The accuracy of height and distance measurement can reach 99.06% and 98.06%.
標(biāo)簽： ARM 單片機(jī) 自動(dòng)
上傳時(shí)間： 2013-10-30
上傳用戶(hù)：jackandlee
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