現有基于MAX7219芯片的數碼管驅動電路只適用于小尺寸LED,為擴展其使用范圍,在介紹動態顯示芯片MAX7219功能的基礎上,提出了一個基于該芯片的8位高亮度8英寸數碼管驅動電路。電路保留了MAX7219芯片的功能強大、編程簡單等優點,通過74LS273鎖存器和ULN2803達林頓驅動器,實現了對任意大尺寸數碼管提供較高電壓和電流驅動的靜態顯示,并亮度可調。
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.
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.
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.
在航電系統維護過程中,為解決定位故障的效率和降低維修成本等問題,提出了基于ICD(Interface Control Document,接口控制文件)的1553B總線的信息監控系統模型。該系統運用數據采集卡對總線中傳輸的信號有無失真、偏差等電氣特性進行檢測,并使用1553B通訊卡通過測控軟件LabWindows/CVI編程與ICD數據庫的動態鏈接,實現總線信息的解析和故障的判斷。與傳統的維護過程相比,這種模型能夠從信號的電氣特性以及信息的解析等全方位的去檢測判斷故障的來源,并且能夠廣泛在其他1553B總線系統內擴展應用。驗證表明該監控系統可以對總線信息進行快速有效地監測分析,能滿足應用需求。
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.
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.
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.
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%.
以太網和CAN總線應用廣泛,但由于其通信協議不同,兩種總線器件間無法進行數據通信,因此,設計了基于CP2200與C8051F040的以太網總線與CAN總線接口轉換電路,并給出部分相關硬件電路與軟件設計分析。在保證數據完整和協議可靠的前提下,通過握手協議和簡化的以太網協議,不僅實現了以太網數據與CAN數據的轉發,同時還順利的解決了以太網的高速性與CAN的低速率沖突,以及兩者數據包之間的大小不同的矛盾。
Abstract: In the development of actual application, Ethernet and CAN bus are used very extensively. Owing to its various communication protocols, the communicating between two kinds of bus device can’t be carried out. Therefore, in order to solve this problem, the Ethernet-CAN bus interface circuit based on CP2200 and C8051F040 was designed in this paper, and part of the related hardware circuit and software design analysis were given. On the condition of data’s integrity and protocols’reliability, through the handshaking protocols and the simplified the Ethernet protocol, not only the data switching between CAN and Ethernet was realized, but also the differ in velocity and packet size was solved.
提出一種基于凌陽單片機的步進電機加減速的控制方法。采用凌陽科技推出的16位結構工控單片機SPMC75F2413A為控制器,由Allegro公司生產的兩相步進電機專用驅動器件SLA7042M構成步進電機的驅動電路,在傳統的3段直線加減速控制算法基礎上增加至7段S形曲線加減速過程,控制步進電機的啟動和停止。實驗結果表明,該控制方法克服了直線加減速中不連續、易造成系統沖擊的問題,整個系統實現柔性控制,電機啟動、停止連續性能提高30%。
Abstract:
The method of controlled stepping motor is referred based on SPMC75F2413A MCU, which adopts the 16 knots SPMC75F2413A MCU as the controller. The special-purpose actuation chip SLA7042M of two stepping motor produced by Allegro Corporation constituted to actuation electric circuit. The purpose of increasing to seven section of S shape curve based on the traditional three sections of straight line is to control the start and stop process of stepping motor. The experimental results show that the control method solves easy to pull-out and overshot problems. The overall system realizes flexible control, and the performance of motor start or stop continuity is increased 30%