利用單片機具有的智能程序控制的特點，設計了基于STC89C52單片機的"二極管特性測試器"，可對二極管一般特性進行快速測試。通過穩定線性電流源給二極管加載恒定電流，然后由高精度模數轉換器測試其壓降，以此為基礎可判斷二極管好壞、檢測二極管極性和測試二極管伏安特性等，避免了用萬用表測試只能測得極性而不知其特性這一缺點。可用于電子設計制作過程中對二極管進行快速測試，以確定被測二極管是否滿足電路的設計要求。 Abstract: By making good use of the intelligent control function of the Micro Controller Unit (MCU)， the diode trait tester was designed based on the STC89C52，which could be used to test the trait of a diode rapidly. By loading constant current to diode through the stable linear current source， and measuring the voltage drop of the diode by high-precision analogue-to-digital converter (ADC)， it can judge whether the diode is good or not， distinguish the polarity of the diode， and test the trait that the diode， which can avoid the fault of using a multimeter can only measure the polarity but not the trait. This device can be used to test the trait of a diode quickly，and to make sure that whether a diode can be used in the electronic design or not.
上傳時間： 2013-11-13
上傳用戶：assef
Digitemp Junior – An RS-232 Port-Powered digital Thermometer Digitemp Jr. is a device that is designed to measure and report ambient temperature. When connected to an RS-232 port on any PC, it will periodically measure and report in ASCII form the ambient temperature in degrees Celsius. These temperature readings can be monitored with any terminal program. If the terminal program supports capture to disk, the temperature readings can be saved to disk for further analysis with a spreadsheet program or other data analysis tool. The simple ASCII output format of Digitemp Jr. makes it rel- atively easy to write custom software for receiving, recording, and analyzing ambient temperature data. Best of all, Digitemp Jr. requires no external power sup- plies or batteries. It is powered directly by the RS-232 port.
上傳時間： 2013-10-21
上傳用戶：baitouyu
為解決電致變色器件的顏色變化受外界環境顏色控制的問題，設計了一種基于單片機的便攜式顏色自適應識別電路。與傳統顏色識別電路相比較，該電路利用數字式的顏色傳感器來獲取外界環境顏色，產生的數字顏色信號易于單片機進行處理。在電路中，下位機部分主要負責獲取電致變色器件變色參數及控制電致變色器件的顏色變化;而上位機部分主要負責把下位機獲取的電致變色器件變色參數進行電壓到顏色的曲線擬合，并通過藍牙通信把擬合曲線參數傳遞給下位機。結果表明，該電路能自動根據環境顏色提供-4~4 V范圍步進為0.1 V的電壓來驅動電致變色器件的顏色顯示，與傳統的顏色識別電路設計相比，識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.
上傳時間： 2013-11-09
上傳用戶：franktu
設計了一種基于PIC16C71單片機的數字水溫配制閥。該配制閥采用NTC熱敏電阻作溫度傳感器，與固定電阻組成簡單分壓電路作為水溫測量電路，利用PIC16C71單片機內置的8位A/D轉換器把熱敏電阻上的模擬電壓轉換為數字量，PIC16C71單片機控制直流電機驅動混水閥調節冷熱水的混合比例實現水溫調節。給出了控制電路圖，對水溫測量電路的參數選擇和測溫精度作了詳細討論。實驗和分析表明，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.
上傳時間： 2013-11-08
上傳用戶：Yue Zhong
針對目前使用的RS232接口數字化B超鍵盤存在PC主機啟動時不能設置BIOS，提出一種PS2鍵盤的設計方法。基于W78E052D單片機，采用8通道串行A/D轉換器設計了8個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送，正交編碼器信號通過XC9536XL轉換為單片機可接收的中斷信號，軟件接收到中斷信息后等效處理成按鍵。結果表明，在滿足開機可設置BIOS同時，又可實現超聲特有功能，不需要專門設計驅動程序，接口簡單，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.
上傳時間： 2013-10-10
上傳用戶：asdfasdfd
隨著單片機功能集成化的發展，其應用領域也逐漸地由傳統的控制，擴展為控制處理數據處理以及數字信號處理，DSP( digital Signal Processing)等領域。凌陽的16位單片機就是為適應這種發展而設計的。
上傳時間： 2013-10-09
上傳用戶：zmy123
提出了一種以S3C2440A為核心處理器的銀行評價器的設計方案，并結合XILINX公司的XL95144XL型CPLD，輔助S3C2440A，實現該銀行評價器的各部分功能以及系統信號之間的相互協調。該評價器在系統設計上采用液晶屏顯示，代替了以往簡單的數碼管電路的顯示模式，在視覺上給人以全新的享受。同時，評價器增加了新的網絡供電方式，只要將評價器連接上網絡就可以正常工作，方便了客戶的使用。總之，此款銀行評價器采用了嵌入式系統的設計方案，大大豐富了系統功能，實現一個銀行評價器設計的新突破。 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.
標簽： S3C2440A
上傳時間： 2013-11-03
上傳用戶：taa123456
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
生活中許多目標的高度和水平距離需要進行測量。目前主要的測量方法，仍以傳統的皮尺丈量為主，測量效率不高，有時還很不方便，沒有技術成熟的數字式測高測距產品。以基本的數學方法為理論依據，利用遙控小車做為載體，采用角度傳感器測量角度、霍爾傳感器測量水平距離等，通過單片機LM3S615進行數據計算，實現了對待測目標物體的高度、水平距離等數據的快速、精確和數字式的測量，高度測量精度可達99.06%，水平測量精度則可達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%.
上傳時間： 2013-10-30
上傳用戶：jackandlee
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
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