便携式信号采集在机器健康诊断系统中有较高的应用价值。机器健康诊断的信号特点是包括低频信号。本文研究是为了实现简易而且低成本的低频便携式信号采集。以Microchip公司单片机PIC18F1320为核心设计信号采集电路，实现了信号的采集和保存。系统采用串行电可擦除芯片24LC32A保存数据，经过有线通信，信号数据由串行口通过MAX232芯片输送到微型计算机接收和保存，最后绘制出信号波形。 微型计算机程序采用Visual Basic编程。研究成功采样频率为3 kHz的复杂信号，证明该方案符合设计要求。 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.
上传时间： 2013-11-19
上传用户：moerwang
为解决电致变色器件的颜色变化受外界环境颜色控制的问题，设计了一种基于单片机的便携式颜色自适应识别电路。与传统颜色识别电路相比较，该电路利用数字式的颜色传感器来获取外界环境颜色，产生的数字颜色信号易于单片机进行处理。在电路中，下位机部分主要负责获取电致变色器件变色参数及控制电致变色器件的颜色变化;而上位机部分主要负责把下位机获取的电致变色器件变色参数进行电压到颜色的曲线拟合，并通过蓝牙通信把拟合曲线参数传递给下位机。结果表明，该电路能自动根据环境颜色提供-4~4 V范围步进为0.1 V的电压来驱动电致变色器件的颜色显示，与传统的颜色识别电路设计相比，识别的精度和速度都得到了明显改善。 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.
上传时间： 2013-11-09
上传用户：franktu
针对目前使用的RS232接口数字化B超键盘存在PC主机启动时不能设置BIOS，提出一种PS2键盘的设计方法。基于W78E052D单片机，采用8通道串行A/D转换器设计了8个TGC电位器信息采集电路，电位器位置信息以键盘扫描码序列形式发送，正交编码器信号通过XC9536XL转换为单片机可接收的中断信号，软件接收到中断信息后等效处理成按键。结果表明，在满足开机可设置BIOS同时，又可实现超声特有功能，不需要专门设计驱动程序，接口简单，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.
上传时间： 2013-10-10
上传用户：asdfasdfd
为了有效地提升铅酸蓄电池的使用寿命，同时实现对充电过程的监控，设计出一种用单片机控制的36 V铅酸蓄电池充电电源。本电路采用反激式拓扑，连续电流工作模式，电源管理IC设计在电源的副边，由ELAN公司的EM78P258N单片机模拟，是用可编程器件模拟电源管理IC，实现智能电源低成本化的一次成功尝试，通过对单片机的软件设计实现了充电电源的状态显示、充电时间控制、报警、过温保护、过压保护、过流保护等功能。本充电器真正的实现了铅酸蓄电池的三段式充电过程，其最高输出功率可达90 W，效率约85%，成本不到20元，具有很高的市场竞争力。 Abstract: In order to extend the life of lead-acid battery efficiently and supervise the charging process meanwhile， a 36V lead-acid battery charge powe supply controlled by microcontroller is designed. The charger is flyback switching power supply and works in CCM mode. A EM78P258N microcontroller made by ELAN microelectronics corporation is used as power management IC which is designed at the secondary circuit. The project is a successful attempt to low-cost intelligent power used microcontroller simulating power management IC. The charger also has the functions of the status reveal， charge time control， alarming， thermal protect， current limit and overvoltage protect by the software design. The circuit actually implements the three-step charge process， whose power is up to 90W and whose efficiency can get 85%. The net cost of this charger is less than 20 RMB， so that the charger is of powerful market competitiveness.
上传时间： 2013-11-16
上传用户：cepsypeng
生活中许多目标的高度和水平距离需要进行测量。目前主要的测量方法，仍以传统的皮尺丈量为主，测量效率不高，有时还很不方便，没有技术成熟的数字式测高测距产品。以基本的数学方法为理论依据，利用遥控小车做为载体，采用角度传感器测量角度、霍尔传感器测量水平距离等，通过单片机LM3S615进行数据计算，实现了对待测目标物体的高度、水平距离等数据的快速、精确和数字式的测量，高度测量精度可达99.06%，水平测量精度则可达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%.
上传时间： 2013-10-30
上传用户：jackandlee
首先研究CAN总线和SAE J1939协议，提出一种基于MC9S12HZ256微控制器的总线式汽车数字仪表解决方案。详细介绍SAE J1939协议的报文帧格式及应用层协议中发动机相关参数的定义，以及步进电机及其驱动和车速信号的处理方法。该数字仪表系统硬件平台由微处理器和信号采集和信息处理及显示等模块组成。软件设计部分编程实现了对CAN总线和各传感器数据的读取、处理。该系统能够实时反映车辆工况。 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.
上传时间： 2013-10-20
上传用户：huannan88
介绍一种以Atmel公司的Attiny13为处理器的投影仪防盗器设计方案。该防盗器具有功耗低，功能完整，防盗效果良好等特点，除具有报警功能外，防盗器还具有以无线方式向主机发送报警信号的功能。采用315MHz发射模块实现无线信号发送。该投影仪防盗器可适应众多厂家生产的防盗器主机。 Abstract: This paper introduces the design scheme of overhead projector's anti-theft device which users ATMEL company’s Attiny13as processor.This anti-theft device features low powerloss，functional integrity，good effect of anti-theft.In addition to its own with alarm functions，the anti-theft device also has alarm function which can send alarm signal to the host through wireless way.It sends wireless signal using315MHz transmitting module，so this overhead projector’s anti-theft device is adapted to anti-theft device host produced by many manufacturers.
上传时间： 2013-11-02
上传用户：ysystc699
介绍了一种TI公司最新推出的MSP430F247单片机，利用它自带的I2C模块驱动I2C总线的温度传感器TMP275。TMP275是一款具有高精度、低功耗的新型温度传感器。由于TMP275具有可编程功能，纤小的封装以及极大的温度范围，因而广泛应用于组建超小型温度测量装置。 Abstract: A new single chip microcomputer MSP430F247 which is released by TI is introduced.It can drive I2C interface digital temperature sensor TMP275 with I2C module.TMP275 is a new temperature sensor which has high accurate,low power. Because TMP275 has programmable function,small packages and wide temperature range,it is applied widely in very little temperature measurment equipment.
上传时间： 2013-12-06
上传用户：asdfasdfd
在汽车发动机起动时，若发动机起动后起动机不能及时断电，将会烧毁起动机或损坏飞轮齿环；若变速器不在空档位置起动，则起动机的瞬间动力将使汽车位移，还可能引起交通事故和人身安全。为此介绍一种利用NXP P89LPC901单片机控制的汽车起动保护控制器，通过检测汽车起动开关、变速箱档位、发动机转速，实现对汽车发动机起动过程检测和保护。起动保护控制器在发动机起动过程中通过采用逐个关闭打开负载系统，解决汽车发动机过程中因起动电流大而对汽车电源的冲击影响,延长了电瓶寿命。 Abstract: When the automotive engine is started, the engine start motor and flywheel gear may be damaged， even traffic accidents and personal safeties may be caused by wrong operation or other factors.In order to ensure the automotive engine can be started normally and safely,it is necessary that the protecting measures and methods are considered in the automotive electrical control system.This paper introduces a kind of the automotive engine starting protect controller based on NXP P89LPC901 MCU.The controller can protect the engine starting process by detecting the starter key switch,transmission stall and engine speed.Through the use of close and open load system,the controller can solve the impact on automotive power because of the high-current load in the process of the automobile engine starting, and extend battery life.
上传时间： 2013-10-15
上传用户：mikesering
Mega16是一款采用先进RISC精简指令，内置A/D的8位单片机，可支持低电压联机 Flash和EEPROM 写入功能；同时还支持 Basic和C 等高级语言编程。用它设计电子时钟不仅成本低，硬件简单，而且很容易实现系统移植。介绍了如何利用AVR系列单片机Mega16及1602字符液晶来设计电子时钟的方法，同时给出了相应的电路原理及部分语言程序。 Abstract: ?Mega16 is a high-performance, low power consumption, the use of advanced RISC concise instructions, built-in A/D 8-bit microcontrollers, the on-line support for low-voltage Flash, EEPROM write function. Except Mega16 also support the Basic, C, and other high-level language programming.The electronic clock which is deisgned by Mega16 is not only low-cost, simple hardware, but easy to achieve system migration.The design method of electrioic clock based on the AVR Mega16 and character LCD1602 is introduced in this paper,and the corresponding circuit electrionic and some language program are given.
上传时间： 2014-12-27
上传用户：zl5712176
