基于TinyOS的嵌入式无线传感器网络设计

TinyOS是专门针对无线传感器网络的一种嵌入式操作系统.以超低功耗单片机MSP430为核心,结合无线收发模块nRF24E1,对无线传感器网络的普通节点和网关节点进行设计,并介绍嵌入式系统的设计与实现.该系统能够满足无线传感器网络低功耗的要求,具有一定的应用价值.     

低功耗无线传感器网络节点设计与实现

本文设计并实现了低功耗无线传感器网络节点.首先分析比较了现有的各种节点设计方案,选取低功耗芯片,设计了基于MSP430F149处理器和nRF24L01+无线收发芯片的低功耗节点设计方案,并提出了低功耗能量管理策略,最后对节点的能量消耗进行了仔细测试和分析.实验结果表明,提出的节点设计方案和能量管理策略能够实现节点的低功耗工作.     

一种数据包长度可变的串口通信系统设计

文章采用DSP加FPGA的结构实现了一种可扩展的新型串口通信系统。新系统使用UART IP核实现串口协议,并在此基础上设计了接收和发送通道。新系统以数据包格式收发串口数据,并支持长度可变的数据包。收发过程完全独立且与主机并行,宿主机只需要进行缓冲区的读写即可完成收发任务。新系统解决了以往使用UART IP核时内建FIFO不可控的问题,提高了数据吞吐量且提升了整个嵌入式系统的执行效率。     

基于MSP430的无线传感器节点动态功率管理研究

针对无线传感器网络节点低功耗设计问题,介绍无线传感器节点组成及其能耗,分析动态功率管理原理及其算法,研究混合自动控制并对其进行改进。改进的混合自动控制算法通过对环境变量的变化值划分来控制无线收发模块的收发频率,能减少收发次数,降低系统功耗。最后介绍了在MSP430,nRF905和SCA3000组成的无线加速度传感器系统中对倾斜角测量时改进的混合自动控制算法的应用。     

精准农业无线传感器网络

设计并实现精准农业无线传感器网路,用于监测农作物生长环境。用高性能、超低功耗单片机MSP430F149设计温湿度和光照强度传感器节点;用高性能32位ARM处理器LM3S6918设计汇聚节点,采用无线射频器件CC1000实现数据的无线收发;针对汇聚节点能量不限的特点,改进传统MAC协议,提出并实现了一种新的MAC层通信协议。实验证明,该网络具有生命周期长、稳定性好的优点,可以满足精准农业的环境监测要求。     

基于nRF905的低功耗温湿度无线测量系统

为实现温湿度测量和无线数据传输,该设计使用AVR系列低功耗单片机ATmega16L作为控制芯片,低功耗芯片nRF905作为无线收发模块,并设计了基于数字温湿度传感器SHT11的温湿度无线测量系统,最后给出该系统的相关硬件组成电路和数据传输流程图。经测试,系统运行稳定可靠,通信距离很远,且温湿度测量精确,具有很广泛的应用前景。     

基于CC2430的无线传感网络中协调器的设计

在无线传感网络中,协调器的作用至关重要。设计了基于CC2430的无线传感网络协调器,并设计了无线接收数据程序及协调器与PC机的串口通信程序。该协调器能够接收无线传感器节点发送的数据,并能将数据通过RS232串口将数据送给PC机上进行显示。所设计的协调器与其他传感器节点构建的无线传感器网络可以应用于粮仓温湿度监测、矿井安全生产等诸多领域。     

基于精简IPv6的自组网络

本文介绍了一种简单易实现的基于精简IPV6的自组网络,设计了微型无线传感器节点,选用了低功耗、低价格的ATMEGA16L单片机和数据无线收发芯片nRF905,实现了一种低功耗无线网络,分析了自组网络的体系结构,为进一步研究基于IPv6的无线传感器网络的其它算法提供了一个非常有价值的参考平台。     

基于剩余能量的最短路径两端匿名路由方案

无线传感器网络由多种传感器节点组成,可以被广泛部署用来监测现实世界中的多个领域.但是,敌手能够找到网络中的源节点和接收节点并进行攻击,因此保护好收发双方的位置至关重要.针对无线传感器网络中位置隐私泄露及现存方案中节点能量消耗不均衡和通信低效的问题,基于网络中节点的剩余能量和距离接收节点的距离,提出了一种保护源节点和接收...     

基于ZigBee与GPRS的雷达阵元多点温度探测及传输系统设计

针对雷达工作环境的温度采集问题,提出基于无线传感器网络技术的多点温度采集系统。以CC2430为主控芯片,采用IEEE802.15.4协议和Z igBee协议,通过星型网络实现主从节点之间数据的采集和传输,利用串口通信技术与GPRS通信,通过SMS短信息的形式将采集到的信息打包发送到远端GPRS接收系统,远端GPRS系统通过其UART端口将传送过来的温度信息发送到C8051F020单片机进行处理及显示。     

基于STC10F04EX的多串口数据收发系统

为了转发水质监测数据,采用新型的1T周期单片机STC10F04EX为控制核心,将双4选1模拟开关4052的2个公用端与单片机的RxD、TxD端连接,通过分时连通的方式,对单片机的UART进行扩展,构成一个多串口的数据转发系统。扩展的串口分别连接到3个不同的水质监测设备,以及一个与无线发射模块。单片机分时得到3个水质监测设备传来的数据,并将得到的数据通过无线模块进行转发,转发距离可达3 000 m。远离现场的计算机完成数据接收及分析。该方法用于对单片机串口扩展和远距离数据传送简洁可靠。所建的数据收发系统,可以同时连接多台串口监测设备,弥补了计算机串口较少的不足,并且功能有别于多串口卡。该系统已成功应用于多传感器水环境监测的数据转发。     

基于DS18B20的短距无线温度检测系统

基于一种新型单线可编程数字温度传感器DS18820的测温原理,以低功耗的MSP430F1611单片机为微控制器,设计了一种的短距无线温度检测系统,并通过无线模块nRF401实现数据的无线收发。给出了微控制模块、LCD显示模块、无线收发模块和温度传感器模块的设计以及系统的软件开发。实验结果表明：系统实现了短距、多点的温度检测;利用无线收发模块和CLD显示模块,节约了现场调试时间,实现了系统的便携式设计并提高了温控系统的稳定性;利用MSP430单片机的超低功耗以及DS18820的单线接口方式,实现了整个系统的低功耗设计,并简化了系统的结构。     

SyncWUF: An Ultra Low-Power MAC Protocol for Wireless Sensor Networks

In wireless sensor networks, power consumption is one of the key design issues because a large number of sensor nodes are powered by cheap batteries. Switching the RF transceiver, which is one of the biggest power consumers in a sensor node, to low-power sleep mode as much as possible has been proven to be a very efficient way to save power with a factor of tens or even hundreds. So far, several schemes have been proposed to reduce the duty cycle of the RF transceiver by MAC layer scheduling. Among them, the wake-up-frame scheme and the WiseMAC are two very efficient protocols based on the so-called preamble sampling technology. This paper proposes combining these two schemes to obtain a further optimized low-power MAC protocol, called SyncWUF, for low-traffic wireless sensor network. Analytical and simulation results prove that our proposal achieves significant battery lifetime gain in different application cases without negatively affecting other important system parameters such as channel capacity and latency     

无线串口在智能终端上的应用

文章介绍了由Silicon Labs的无线收发芯片Si4432以及低功耗单片机C8051F930构成的无线串口收发系统的硬件实现原理以及数据收发流程。在无线透明串口数据收发的基础上,文章提出在无需拆卸智能终端以及开盖操作的前提下,通过无线串口实现对智能终端的嵌入式操作系统、应用软件、播放文件、广告等文件的实时更新的方法。该方法保证了系统长期工作的稳定性,并大大提高了工作效率。     

基于CC2420的无线传感器网络节点的设计

CC2420是Chipcon公司开发的一款符合Z igbee标准的低功耗射频芯片。在简要介绍无线传感器网络节点结构后,对CC2420芯片的功能特点进行了分析,并结合其工作原理和应用电路,设计了以ATmega128L为处理器、CC2420芯片为无线通信芯片的无线传感器网络节点。     

电机温度监测系统低功耗无线节点模块设计

提出了一种用于电机温度监测系统的无线数据收发节点模块设计方案,利用LPC1114的省电耗模式配合Si4432集成芯片实现无线收发模块的低功耗。另外,针对模块硬件实现RF前端高频电路设计和前期仿真做出详细说明,模块的RF性能指标分别做了测试,分析了本模块的耗能数据,可以满足大部分的低功耗、低速率、高灵敏度的实时无线数据传输需求,本模块已经可靠、稳定地应用于系统中。     

A TinyOS-enabled MICA2-based wireless neural interface

Existing approaches used to develop compact low-power multichannel wireless neural recording systems range from creating custom-integrated circuits to assembling commercial-off-the-shelf (COTS) PC-based components. Custom-integrated-circuit designs yield extremely compact and low-power devices at the expense of high development and upgrade costs and turn-around times, while assembling COTS-PC-technology yields high performance at the expense of large system size and increased power consumption. To achieve a balance between implementing an ultra-compact custom-fabricated neural transceiver and assembling COTS-PC-technology, an overlay of a neural interface upon the TinyOS-based MICA2 platform is described. The system amplifies, digitally encodes, and transmits neural signals real-time at a rate of 9.6 kbps, while consuming less than 66 mW of power. The neural signals are received and forwarded to a client PC over a serial connection. This data rate can be divided for recording on up to 6 channels, with a resolution of 8 bits/sample. This work demonstrates the strengths and limitations of the TinyOS-based sensor technology as a foundation for chronic remote biological monitoring applications and, thus, provides an opportunity to create a system that can leverage from the frequent networking and communications advancements being made by the global TinyOS-development community.     

On subsurface wireless data acquisition system

Measurement, evaluation, and monitoring of subsurface objects often require wireless data transmission between an embedded sensor and an exterior host system. Such technologies find applications in many areas-medical imaging, space exploration, earth formation evaluation in oilfield industries, for example. This paper describes a complete wireless data acquisition system that includes design of a transceiver unit, as well as communication protocols for data encoding and decoding. Although the application considered in this paper pertains to the oilfield industry, the method is applicable to other areas as well. The transceiver design is highly constrained due to requirements on physical size, mechanical stability, and low-power consumption. The host antenna generally consists of ferrite-backed coils wound on a metallic cylinder. A critical requirement in the design of these coils is to produce a desired spatial variation of the magnetic field in a specified region. A genetic algorithm is used to optimize the location and excitation of each coil. A combination of finite-element method and superposition principle is used to speed up the solution of forward problem. The data measured by an embedded sensor are encoded with seven-bit cyclic redundancy code concatenated with Manchester code for error detection/correction and bit synchronization. Coded data are finally transmitted by binary frequency-shift keying modulation scheme. Numerical and experimental results for magnetic field, signal-to-noise ratio, and data demodulation are presented.     

Analysis and design of a frequency-hopped spread-spectrumtransceiver for wireless personal communications

Personal communications services (PCS) require low-power radio technologies. One such transceiver architecture employing frequency-hopped spread-spectrum techniques is presented. System features such as antenna diversity with equal-gain combining and sequential hop combining are incorporated into the transceiver design to achieve robust wireless digital data transmission over fading channels. A direct-conversion architecture from radio frequency (RF) to baseband reduces the overall power consumption by eliminating intermediate frequency (IF) components. High-rate frequency hopping with frequency-shift keying (FSK) modulation is implemented using a direct digital frequency synthesis technique. A multiplierless correlation FSK detector, suitable for direct-conversion receivers, has been designed for quadrature noncoherent detection. Robust acquisition algorithms based on energy detection and pattern matching and tracking architectures using digital phase-locked loops are also described for system synchronization. The proposed transceiver is well-suited for low-power PCS applications and other portable wireless communications