基于mbed的无线体重计快速设计

基于ARM公司的ARM mbed IoT云端软件平台和意法半导体推出的Nucleo开发套件,将HX711采集到的压感数据进行采集和处理,得到体重数据后,通过蓝牙BLE的GATT协议将相应数据进行传输,在安卓智能设备端编写支持蓝牙BLE的APP,接收并显示体重数据,这种无线蓝牙体重计原型的快速开发和验证显示了mbed平台易于开发和高效便捷的特性.     

Feasibility and performance evaluation of a 6LoWPAN‐enabled platform for ubiquitous healthcare monitoring

Technology has revolutionized medical practices by enabling more convenient and non‐intrusive monitoring of patient's health, leading to next generation ubiquitous healthcare (u‐healthcare). The exploitation of the Internet protocol version 6 addressing space along with the miniaturization of electronic devices has fostered providing interoperability and connectivity of wearable sensor devices in wireless body area networks to the Internet of Things. In this paper, we propose to integrate the IPv6 over low power wireless personal area network (6LoWPAN) to the u‐healthcare monitoring system architecture. The main objective is to study the feasibility of the 6LoWPAN‐enabled platform in real‐world scenarios dealing with medical data. The performance evaluation of this platform is carried out initially through simulations using OMNet++ and then supported by an experimental study using sensor motes and a customized micro‐computing unit. Performance metrics such as throughput, end‐to‐end delay, packet error rate, and energy consumption are investigated under acute health conditions, where patient's health information has to be sent continuously and at maximum rate to the care provider. The obtained results show that the proposed 6LoWPAN solution fulfills the main quality of service requirements of u‐healthcare applications. Copyright © 2015 John Wiley & Sons, Ltd.     

基于BLE4.0姿态解算的无线语音鼠标设计

设计了一款残疾人专用智能无线语音鼠标,让双手不灵活的残疾人灵活地操纵电脑成为现实.本设计发送端采用BLE4.0技术负责头部姿态解算、语音识别、向电脑发送操作指令等功能.无需任何接收装置,只需与电脑自带的蓝牙设备配对后便可通过相应的蓝牙协议对电脑直接进行操控.     

基于二次剩余的低功耗蓝牙用户认证方案

针对低功耗蓝牙协议栈安全机制中缺乏用户身份合法性认证的问题,首先分析并指出了已有蓝牙用户认证协议无法抵抗假冒和窃听攻击,且无法适用于低功耗蓝牙协议;其次结合低功耗蓝牙协议层次设计了用户认证模型,构建了基于二次剩余的低功耗蓝牙用户认证方案。通过中国剩余定理求解二次剩余,完成用户身份双向认证,同时满足用户匿名要求。安全性分析表明方案可以有效地抵御用户口令泄露、从设备丢失、假冒及窃取用户隐私等攻击方式。理论分析及实验结果表明具有较高的计算效率和较小的存储开销,适用于资源受限的低功耗蓝牙可穿戴设备应用场景。     

Indoor BLE and MEMS based multi-floor fusion positioning algorithm

Based on the data fusion from micro electro mechanical system (MEMS) sensors and low-power bluetooth (BLE),an indoor BLE and MEMS based multi-floor positioning algorithm was proposed.First of all,the affinity propagation clustering,outlier detection and received signal strength indicator (RSSI) filtering algorithms were applied to denoise the fingerprint database.Second,by using the extended Kalman filter,the robust M estimation algorithm was used to perform the optimal estimation of the two-dimensional target position.Finally,the barometer output and geographical position information was considered to realize the height estimation of the target.The experimental results show that the proposed system is able to achieve the horizontal and vertical positioning errors lower than 0.7 m and 0.35 m respectively in multi-floor fusion positioning.     

A coin-battery-powered LDO-Free 2.4-GHz Bluetooth Low Energy/ZigBee receiver consuming 2 mA

This paper describes a 1.5-V low dropout regulator (LDO)-free ultra-low-power 2.4-GHz CMOS receiver for direct-powering through a coin battery. By effective merging the quadrature low noise amplifier (LNA), in phase and quadrature (I/Q) mixers, a voltage controlled oscillator (VCO) and a trans-impedance amplifier (TIA) in one cell, while removing the LDO, we fully utilize the available 1.5-V voltage supply for current-reuse between blocks, minimizing the dc current consumption. Specifically, a quadrature LNA operating as both common-source and common-drain provides the I/Q outputs in the signal path. Forward-body-bias applied to the transconductance stage of the I/Q mixers relaxes their voltage headroom consumption. Prototyped in 180-nm CMOS, the receiver exhibits a conversion gain (CG) of 23 dB, a noise figure (NF) of 13.8 dB and an input-referred 3rd-order intercept point (IIP3) of −14 dBm while consuming only 2 mA. The phase noise of the VCO is −118.5 dBc/Hz at 2.5 MHz offset. The low-cost technology and low current consumption renders the receiver suitable for Internet of Things (IoT) devices using the Bluetooth Low Energy (BLE) or ZigBee standards.     

BLE Mesh组网的可穿戴设备低功耗研究

针对目前可穿戴式设备功耗高的问题,本文进行了基于BLE Mesh组网的可穿戴设备低功耗的研究.以可穿戴单兵冲击波损伤测评系统为例,设计了一款基于Mesh组网的单兵冲击波损伤测评系统,该系统在原有系统的基础上增加了一个蓝牙组网.由于可穿戴设备采用纽扣电池供电,为了保证该系统的功耗不能有大幅度的增加,本文采用泛洪算法和低功...     

基于线性高压恒流驱动的智能LED灯设计

文章设计了一款智能LED产品,该产品包括了蓝牙4.0 BLE模块、电源模块和线性高压恒流驱动芯片。智能LED灯内嵌的蓝牙4.0 BLE模块实现和智能手机的通信,同时通过IIC协议和线性高压恒流驱动芯片接口,获取LED灯的调光调色控制命令。采用非隔离线性高压恒流驱动方案,利用芯片SM2135的PWM技术实现LED灯的调光调色。该方案设计的智能LED灯具有控制电路简单、功率因数高、成本低、控制灵活的特点,通过具有蓝牙功能的智能手机可以自由选择照明方式,充分体现了智能LED灯的智能化和个性化特点。     

Light emission from oxygen covered Al and Cu surfaces

Ion beam induced light emission is used to investigate the sputtering yield, S_O, of oxygen atoms on the surfaces of a polycrystalline copper and an Al(1 1 1) target. Under Ar⁺ and Ne⁺ ion bombardment of Al(1 1 1) and polycrystalline copper targets, spectral lines of Cu I and Al I emitting from sputtered excited atoms are measured as a function of the oxygen partial pressure, wavelength and beam energy. The light emission for two Al I lines (3082 and 3962 Å) and Cu I lines (3247 and 3274 Å) are proportional to the oxygen partial pressure (1×10⁻⁴ Torr). Above 2×10⁻⁴ Torr, the light intensities start to decrease which is consistent with other measurements. From saturated-oxygen covered target surfaces, light intensities of Al I and Cu I lines are measured as a function of time and oxygen partial pressures. The sputtering yields could be determined from the curves of spectral lines directly. For 10 and 20 keV Ar⁺ ions bombarding the copper surface, the oxygen sputtering yields are 0.34 and 0.22 (atoms/ion), respectively. The same copper target was bombarded by Ne⁺ ions at 5 and 10 keV, the oxygen sputtering yields are 0.87 and 0.59, respectively. For 10, 15, and 20 keV Ar⁺ bombarding an Al(1 1 1) target, the obtained sputtering yields are 0.44, 0.31, and 0.2 (atoms/ion), respectively.     

人员定位系统在水电工程施工过程中的应用与研究

本文主要以目前国内外应用最为广泛的基站定位技术、LBS定位技术、差分GPS定位技术和BLE定位技术及大数据处理分析技术作为研究对象,对在水电施工建设中的应用做了研究,测试结果表明,定位精度和系统时延满足水电建设管理的需求,可在水电建设中推广应用.