Most portable computers have built-in sockets to acceptsmall PC cards for use as extended memories, fax modems,network interfaces, wireless communicators and awide assortment of other functions. The Personal ComputerMemory Card International Association (PCMCIA)has released specifications that outline the general powerrequirements for these cards.
上传时间： 2013-11-18
上传用户：bcjtao
This white paper raises some fundamental issues the design engineer should address before deciding upon a communication approach for a wireless network. As no universal wireless network solution exists, it should be custom tailored to suit the application demands. Defining your application communication characteristics is the key to ensure optimal communication reliability and resistance to interfering noise sources.
上传时间： 2013-11-23
上传用户：zhichenglu
以C8051F020为核心处理器，设计无线传感器网络数据采集系统。系统采用SZ05-ADV型无线通讯模块组建Zigbee无线网络，结合嵌入式系统的软硬件技术，完成终端节点的8路传感器信号的数据采集。现场8路信号通过前端处理后，分别送入C8051F020的12位A/D转换器进行转换。经过精确处理、存储后的现场数据，通过Zigbee无线网络传送到上位机，系统可达到汽车试验中无线测试的目的。 Abstract: This paper designs a wireless sensor network system for data acquisition with C8051F020 as core processors.The system used SZ05-ADV wireless communication module，set up a Zigbee wireless network， combined with hardware and software technologies of embedded systems，completed the end-node 8-locale sensor signal data acquisition.Eight locale signals were sent separately into the 12-bit ADC of C8051F020 for conversion through front treatment.After accurate processing and storage，the locale data was transmitted to the host computer through Zigbee wireless.The system achieves the purpose of wireless testing in vehicle trial.
标签： C8051F020 Zigbee 汽车测试 系统设计
上传时间： 2013-11-23
上传用户：dsgkjgkjg
为提高温度测量效率，降低系统的成本，扩展传输距离，设计出一种新型温度采集系统。单片机通过控制具有单总线方式的温度传感器DS18B20实现对温度的测量，同时单片机通过控制具有单总线方式300～450MHz频率范围内的MAX7044与MAX7033无线发射与接收芯片实现温度数据的无线传输。与传统温度采集系统相比，该系统利用单总线方式连接，采用无线传输方式实现远距离通信，易于系统的集成与扩展。实验结果表明，该系统结构简单、方便移植，能够同时实现多达上百点温度的测量与500m范围的传输。 Abstract: To improve the temperature measurement efficiency and reduce system cost,expansion of transmission distance,a new type of temperature acquisition system is designed.Microcontroller controlled temperature sensor DS18B20which has a single-bus achieves temperature measurement,while microcontroller by controlled the MAX7044and MAX7033chip with a single-bus and having300~450MHz radiofrequency to achieve the wireless transmission of temperature data.Compared with conventional temperature acquisition system,the system uses single-bus connected,and uses wireless transmission means to achieve long-distance communications,easy-to-system integration and expansion.The experimental results show that the system is simple,convenient transplantation,and can be implemented in as many as a hundred-point temperature measure-ment and the transmission range of500meters.
上传时间： 2013-10-29
上传用户：515414293
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
从系统硬件设计和软件构成上，介绍一种以AT89C52单片机为核心,通过无线遥控方法实现对预设电话自动拨号报警的智能呼救系统。系统提供了患者在紧急情况下无法使用电话报警时的一种报警手段。由用户预设的多组电话号码作为语音报警对象,预录可长达20 s的语音信号来说明患者所处地点及病情，并通知患者家人。 Abstract: This paper introduces a intelligent alarming system which is realized by wireless remote control system.This system chiefly consists of AT89C51 the system can processor.User can input several groups of telephone number regarded as alarming objects,The system can record some information 20 seconds to tell the site of the patient.And notice the rokonok of the patient.
上传时间： 2013-11-19
上传用户：wd450412225
基于CC1110单片机公交报站系统主要由CC1110单片机最小系统和WT588D语音模块组成，提出了如何实现语音报站，通过无线通信SimpliciTI网络协议实现公交站台的自动播报和OLCD液晶显示公交运行的各类信息。结果表明，该公交报站系统报站准确率99%，价格比同类产品下降了300%以上，系统组成结构简单，提高了系统的抗干扰性和稳定性，也便于携带。 Abstract: The bus stop announcement system based on CC1110 MCU is composed of CC1110 MCU minimum system and WT588D voice module. How to achieve the voice announcing is put forward.The bus-stop will announce automatically and display on the OLCD by means of wireless communication SimpliciTI network protocol. As a result， the bus station stop announcement systems reported 99% accuracy rate， price of similar products declined by 300% or more， system of simple structure， improve the anti-jamming and stability of the power system， it is also portable.
上传时间： 2013-10-21
上传用户：baby25825
基于幅移键控技术ASK（Amplitude-Shift Keying），以C8051F340单片机作为监测终端控制器，C8051F330D单片机作为探测节点控制器，采用半双工的通信方式，通过监控终端和探测节点的无线收发电路，实现数据的双向无线传输。收发电路采用直径为0.8 mm的漆包线自行绕制成圆形空心线圈天线，天线直径为（3.4±0.3）cm。试验表明，探测节点与监测终端的通信距离为24 cm，通过桥接方式，节点收发功率为102 mW时，节点间的通信距离可达20 cm。与传统无线收发模块相比，该无线收发电路在受体积、功耗、成本限制的场合有广阔的应用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
上传时间： 2013-10-19
上传用户：xz85592677
为了提高环境参数采集的自动化水平，提升效率，设计了无线传感器系统。本系统运用了传感器技术、通信技术和单片机技术，实现了对环境温度、湿度、光照度以及可燃性气体浓度等参数的检测。它能够实时地与上位机进行无线通信，满足对环境参数实时监测的要求。 Abstract: In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters，the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring，communication and single-chip microcomputer，it realized real-time monitoring environment parameters,such as temperature，humidity，illumination，concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers，satisfy the desire of real-time monitoring.
上传时间： 2013-11-22
上传用户：longlong12345678
为解决输油管道温度压力参数实时监测的问题，设计了以C8051F930单片机作为控制核心的超低功耗输油管道温度压力远程监测系统。现场仪表使用高精度电桥采集数据，通过433 MHz短距离无线通信网络与远程终端RTU进行通信，RTU通过GPRS网络与PC上位机进行远程数据传输，在上位机中实现数据存储和图形化界面显示，从而实现输油管道温度压力参数的实时监测和异常报警。经实验证明，该系统的12位数据采集精度满足设计要求，漏码率小于1%，正常工作时间超过5个月，能实时有效地监测输油管道的温度压力参数，节省大量人工成本，有效预防管道参数异常造成的经济损失和环境污染。 Abstract: In order to solve the problems on real-time monitoring of pipeline temperature and pressure parameters， the ultra-low power remote pipeline temperature and pressure monitoring system was designed by using the single chip processor C8051F930 as the control core. The high-precision electric bridge was used in field instruments for data collection， the 433MHz short-range wireless communication network was used to make communication between field instrument and RTU， the GPRS was used by the RTU to transmit data to the PC host computer， and the data was stored and displayed in the PC host computer， so the real-time monitoring and exception alerts of pipeline temperature and pressure parameters were achieved. The experiment proves that the system of which error rate is less than 1% over five months working with the 12-bit data acquisition accuracy can effectively monitor the pipeline temperature and pressure parameters in real time， it saves a lot of labor costs and effectively prevents environmental pollution and economic losses caused by abnormal channel parameters.
上传时间： 2013-11-07
上传用户：cuibaigao
