该系统由单片机89S52控制模块，程控宽带放大模块，整形模块，FPGA内频率、相位差测量模块等构成，采用等精度测频法测出频率和周期，可测量有效值为0.01～5V，频率范围1Hz～20MHz信号的频率、周期信号，精度高达10-6。采用计数法测量相位差，该系统可测量有效值0.5～5V，频率10Hz～100kHz信号的相位差，精度为1°。系统功能由按键控制，测量结果实时显示，人机界面友好。 Abstract: The system consists of the following functional blocks:89S52microcontroller controlling module,programmable amplifier module,comparator module,frequency and phase difference testing module in the FPGA.The system use the equal accuracy frequency-examining technique it measures frequency and circle of signal which its ranges is from1Hz to20MHz and the amplitude of which its range is from0.01Vrms to5Vrms,precision is up to10-6.Using of count method,the system detects the phase difference of signal,the amplitude of whic its range is from0.5Vrms to5Vrms and the frequency of which its ranges is from10Hz to100kHz,precision is up to1°,The system functions is controlled by certain keys,measurement results are displayed in real-time and it is friendly interface.
上传时间： 2013-11-04
上传用户：CHINA526
以89S52单片机和EP1C6Q240C8型FPGA为控制核心的多功能计数器，是由峰值检波、A/D转换、程控放大、比较整形、移相网络部分组成,可实现测量正弦信号的频率、周期和相位差的功能。多功能计数器采用等精度的测量方法，可实现频率为1Hz～10MHz、幅度为0.01～5Vrms的正弦信号的精确测频，以及频率为10Hz～100kHz、幅度为0.5～5Vrms的正弦信号精确测相。液晶显示器能够实时显示当前信号的频率、周期和相位差。该多功能计数器精度高，界面友好，实用性强。 Abstract: A multi-function counter，which uses89S52MCU and EP1C6Q240C8FPGA as a control core，consists of peak detector，A/D conversion，program-controlled amplification，compared shaping and phase-shifting network part.The counter measures the frequency，period and phase of sinusoidal signal.With the equal precision method,the multi-function counter achieves the precise frequency measurement of the sinusoidal signal which its frequency is from1Hz to10MHz，its amplitude is from0.01Vrms to5Vrms，as well as the accurate phase measurement of the sinusoidal signal which its frequency is from10Hz to100kHz，its amplitude is from0.5Vrms to5Vrms.The LCD monitor real-time displays the frequency，period and phase difference of current signal.The multi-function counter features high precision，friendly interface，and strong practical.
上传时间： 2013-11-15
上传用户：gy592333
This application report discusses the design of non-invasive optical plethysmographyalso called as pulsoximeter using the MSP430FG437 Microcontroller (MCU). Thepulsoximeter consists of a peripheral probe combined with the MCU displaying theoxygen saturation and pulse rate on a LCD glass. The same sensor is used for bothheart-rate detection and pulsoximetering in this application. The probe is placed on aperipheral point of the body such as a finger tip, ear lobe or the nose. The probeincludes two light emitting diodes (LEDs), one in the visible red spectrum (660nm) andthe other in the infrared spectrum (940nm). The percentage of oxygen in the body isworked by measuring the intensity from each frequency of light after it transmitsthrough the body and then calculating the ratio between these two intensities.
标签： Pulsoximeter Single-Chip Des
上传时间： 2013-10-27
上传用户：黑漆漆
This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上传时间： 2014-01-24
上传用户：s363994250
代码名称： Snitz Forums 2000 代码语言： 英文 代码类型： 国外代码 运行环境： ASP 授权方式： 免费代码 代码大小： 530kb 代码等级： 3 整理时间： 2006-3-15 16:42:00 联 系 人： 开 发 商： 演示地址： 简 介： Snitz Forums 2000, one of the best ASP based bulletin board systems on the market. Getting better every day! A complete board system (forum) that allows the user access to a friendly and intuitive interface. Snitz Forums 2000 v3.4.05 [74]
上传时间： 2015-06-03
上传用户：caixiaoxu26
Introducing a new product requires the designer to think about the product differentiators. Designing a user-friendly product, considering all other features are equivalent, will help increase the product acceptance and sales. A good User Interface is definitively one of these differentiators. In many instances, a Graphical User Interface (GUI) is the best approach.
标签： product differentiators Introducing the
上传时间： 2015-07-04
上传用户：cx111111
A Java package (library/API) to connect and use the Yahoo Instant Messager and Chat protocols (YMSG), in a reasonably coder-friendly and abstract way. Although methods the API exposes are closely matched to Yahoo IM features, the API attempts to hide Download jYMSG API - Yahoo IM Jars
标签： and protocols Messager Instant
上传时间： 2015-09-14
上传用户：zhaiyanzhong
In 1960, R.E. Kalman published his famous paper describing a recursive solution to the discretedata linear filtering problem [Kalman60]. Since that time, due in large part to advances in digital computing, the Kalman filter has been the subject of extensive research and application, particularly in the area of autonomous or assisted navigation. A very “friendly” introduction to the general idea of the Kalman filter can be found in Chapter 1 of [Maybeck79], while a more complete introductory discussion can be found in [Sorenson70], which also contains some interesting historical narrative.
标签： R.E. discretedata describing published
上传时间： 2015-10-22
上传用户：a673761058
Linux in a Nutshell, 5th Edition By Stephen Figgins, Robert Love, Arnold Robbins, Ellen Siever, Aaron Weber ... ... ... ... ... ... ... ..... Publisher: O Reilly Pub Date: July 2005 ISBN: 0-596-00930-5 Pages: 944 Over the last few years, Linux has grown both as an operating system and a tool for personal and business use. Simultaneously becoming more user friendly and more powerful as a back-end system, Linux has achieved new plateaus: the newer filesystems have solidified, new commands and tools have appeared and become standard, and the desktop--including new desktop environments--have proved to be viable, stable, and readily accessible to even those who don t consider themselves computer gurus.
标签： Nutshell Edition Figgins Stephen
上传时间： 2015-12-03
上传用户：frank1234
《JavaServer Faces》 In JavaServer Faces, developers learn how to use the new JavaServer Faces framework to build real-world web applications. The book contains everything you ll need: how to construct the HTML on the front end how to create the user interface components that connect the front end to your business objects how to write a back-end that s JSF-friendly and how to create the deployment descriptors that tie everything together. This book is a complete guide to the crucial new JSF technology.
标签： JavaServer Faces developers framew
上传时间： 2016-01-02
上传用户：redmoons
