603 research outputs found

    Interconnection of IEEE 802.15.4 and Ethernet networks

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    Táto práca sa venuje probému prepojovania rôznych typov sietí, konkrétne sietí typu IEEE 802.15.4 a Ethernetu. Motivácia vychádza zo stále sa rozširujúceho využitia bezdrátových senzorických sietí, potreby zberu dát z nich a ich integrácie. To vyžaduje aby sieť obsahovala prvky schopné preniesť dáta z bezdrátovej siete do okolitého sveta a prípadne poskytnúť konfiguračné a riadiace informácie do vnútra siete. Z hľadiska protokolov a programového vybavenia sa prepojenie uskutočňuje na rôznej úrovni, od sieťovej až po aplikačnú vrstvu komunikačného modelu ISO/OSI, s podporou hardvéru na fyzickej a linkovej vrstve.This work is devoted to the problem of interconnection of different network types, specifically IEEE 802.15.4 and Ethernet networks. Motivation for implementing such an interconnection arises from increased use of WSNs (Wireless Sensor Networks) penetrating many of today's segments of human activity. Deployment of WSNs stems out of the need of controlling and/or monitoring of environment this network is attached to. This usually implies the existence of some kind of Gateway nodes capable of relaying of measured data from inside of the WSN to the outside world and/or providing configuration information and control commands to the WSN. A Gateway usually accomplishes this by interconnecting the WSN with other types of networks acting as a border element. There are different types of Gateways with different capabilities regarding to the network operation, all dependent on a particular network in use. On the software part the interconnection may be done from Network up to Application layer of the ISO/OSI model. Hardware interfaces Physical and Data-Link layers and of course has to be capable of running interfacing software (which may be rather complex). So there is always balance between the system complexity and sufficient capabilities.

    Little Core Based System on Chip Platform for Internet of Thing

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    Although the technology scaling has enabled designers to integrate a large number of hardware blocks onto a single chip realizing System on Chip (SoC), problems arising from leakage current have made power reduction an important issue. The IoT platform has restricted power consumption because of battery power. In this paper, we propose our little core based IoT platform focusing on the low power and expandability. The experimental results demonstrate the feasibility of our proposal to the IoT

    A Low-Power DSP Architecture for a Fully Implantable Cochlear Implant System-on-a-Chip.

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    The National Science Foundation Wireless Integrated Microsystems (WIMS) Engineering Research Center at the University of Michigan developed Systems-on-a-Chip to achieve biomedical implant and environmental monitoring functionality in low-milliwatt power consumption and 1-2 cm3 volume. The focus of this work is implantable electronics for cochlear implants (CIs), surgically implanted devices that utilize existing nerve connections between the brain and inner-ear in cases where degradation of the sensory hair cells in the cochlea has occurred. In the absence of functioning hair cells, a CI processes sound information and stimulates the nderlying nerve cells with currents from implanted electrodes, enabling the patient to understand speech. As the brain of the WIMS CI, the WIMS microcontroller unit (MCU) delivers the communication, signal processing, and storage capabilities required to satisfy the aggressive goals set forth. The 16-bit MCU implements a custom instruction set architecture focusing on power-efficient execution by providing separate data and address register windows, multi-word arithmetic, eight addressing modes, and interrupt and subroutine support. Along with 32KB of on-chip SRAM, a low-power 512-byte scratchpad memory is utilized by the WIMS custom compiler to obtain an average of 18% energy savings across benchmarks. A synthesizable dynamic frequency scaling circuit allows the chip to select a precision on-chip LC or ring oscillator, and perform clock scaling to minimize power dissipation; it provides glitch-free, software-controlled frequency shifting in 100ns, and dissipates only 480μW. A highly flexible and expandable 16-channel Continuous Interleaved Sampling Digital Signal Processor (DSP) is included as an MCU peripheral component. Modes are included to process data, stimulate through electrodes, and allow experimental stimulation or processing. The entire WIMS MCU occupies 9.18mm2 and consumes only 1.79mW from 1.2V in DSP mode. This is the lowest reported consumption for a cochlear DSP. Design methodologies were analyzed and a new top-down design flow is presented that encourages hardware and software co-design as well as cross-domain verification early in the design process. An O(n) technique for energy-per-instruction estimations both pre- and post-silicon is presented that achieves less than 4% error across benchmarks. This dissertation advances low-power system design while providing an improvement in hearing recovery devices.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91488/1/emarsman_1.pd

    Increasing the Reliability of Software Systems on Small Satellites Using Software-Based Simulation of the Embedded System

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    The utility of Small Satellites (SmallSats) for technology demonstrations and scientific research has been proven over the past few decades by governments, universities, and private companies. While the research and technology demonstration objectives that can be provided by these SmallSats are becoming similar to larger spacecraft, their reliability still falls behind. This is in part due to the reduced cost of SmallSat missions in comparison to large spacecraft, which requires cheaper components, rapid development schedules, and accepted risk. In these missions, the importance of the flight software is often overlooked, and the software is rushed through development and not fully tested to provide the reliability required for on-orbit operations. This research aims to investigate the common causes of failures on SmallSats, and to provide a solution to the problem of developing and testing reliable flight software, through the use of software-based simulation of the full embedded satellite system. Through the course of this research, an open-source product was developed and released to the public to assist SmallSat missions, which is currently in use by public and private institutions across the country. The resulting product, the NASA Operational Simulator for Small Satellites, commonly referred to as NOS3, will be discussed in detail. The results of NOS3 will be viewed through a case study of the application of NOS3 to a SmallSat mission

    Surfing the Internet-of-Things: lightweight access and control of wireless sensor networks using industrial low power protocols

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    Internet-of-Things (IoT) is emerging to play an important role in the continued advancement of information and communication technologies. To accelerate industrial application developments, the use of web services for networking applications is seen as important in IoT communications. In this paper, we present a RESTful web service architecture for energy-constrained wireless sensor networks (WSNs) to enable remote data collection from sensor devices in WSN nodes. Specifically, we consider both IPv6 protocol support in WSN nodes as well as an integrated gateway solution to allow any Internet clients to access these nodes.We describe the implementation of a prototype system, which demonstrates the proposed RESTful approach to collect sensing data from a WSN. A performance evaluation is presented to illustrate the simplicity and efficiency of our proposed scheme

    Mobile robot electronic system with a network and microcontroller based interface

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    Integrated Masters at Electronics and Computers EngineeringNowadays mobile robots are expected to be a desire at several services to afford man facilities and increase safety in any kind of duties. Mobility is a key issue in robotics and a challenging subject for any research and development. It combines cognitive capabilities focused on sensorial input and human interaction with intelligent control of the drive systems and requires real mechatronics engineering solutions to enable robust and reliable operation. In the European Centre for Mechatronics [W1] mobile robots have been research subjects for years. A mobile platform with semi-autonomous functionality has been developed years ago. It has been used as a demonstration and test platform to study mobility and cognitive control. In the University of Minho [W3] and RWTH University [W2] that kind of research is also important and the industry support gives a solid development sign to the institutions. As the control system capacity on board of the vehicle has reached limits, a new system architecture with more powerful controller elements was planned to replace the old one. In this context the key objective of the project was to design and develop a new embedded system capable of controlling the mobile platform drives using ATMega microcontroller technology

    SOFTWARE AND HARDWARE DESIGN OF A MINIATURIZED MOBILE AUTONOMOUS ROBOT, OPERATING IN A WIRELESS SENSOR NETWORK

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    Nowadays wireless nodes are becoming more and more popular in the field of localization. Thanks to the high research effort in this area, wireless sensors become more and more sophisticated. From year to year the accuracy in terms of distance estimation increases. In comparison to other localization devices like a Local Positioning System (LPS) or Global Positioning System (GPS), the wireless nodes are considered as a cheap alternative. The Finnish defence department, police and fire department support current research activities within this area, in the hope that they will get beneficial applications. The target of this Master’s Thesis “Software and Hardware Design of a Miniaturized Mobile Autonomous Robot, Operating in a Wireless Sensor Network” was the construction of miniaturized autonomous robot acting within a Wireless Sensor Network (WSN). The robot consists of an Embedded Linux PC, a wireless node and a mobile platform that are connected with each other. In this Master’s Thesis we describe the software and hardware tasks that were necessary for the interaction between the three mentioned components. We also discuss the software implementation for the communication between the wireless nodes and the results of the distance measurements.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Wireless mains sensor for monitoring domestic energy consumption

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    Abstract. Past studies have shown that awareness of energy consumption can lead to reduction in electricity usage and that real-time, per-appliance data on electricity consumption would provide greater utility and actionable information. Yet, the customers of today’s utility companies typically have to be content with data that is aggregated, delayed and difficult to access. Comprehensive real-time data would also aid in optimizing energy consumption with respect to dynamic pricing and avoiding peak consumption periods. The objective of this thesis was to design and manufacture a wireless sensor for continuous and real-time metering of the energy consumption of a household in the UBI-AMI system version 2. The resulting Mains sensor reads the total energy consumption from the kilowatt hour meter using either a galvanic or an optical connection. The individual loads of the fuses in the circuit breaker panel are measured with Hall sensors. An 8-bit microcontroller collects analog measurements, conducts 10-bit ADC and transmits the resulting digital data to the UBI-AMI system using a commercial 6LoWPAN radio module and the CoAP protocol. The data enables the differentiation of the energy consumption of integrated and built-in elements such as floor heating and sauna from the total energy consumption of the household. The Mains sensor was tested with a demonstrator that comprised of a fuse board, a kilowatt hour meter and sockets for connecting loads. The Mains sensor was found to be flawless in reading the total energy consumption from the kilowatt hour meter using a galvanic connection. The sensor was able to read 84% of fast pulses and showed 4% surplus with slow pulses if the optical connection was used. The Hall sensors had a maximum average error of 0.47% with an active power, in comparison to a commercial energy meter. These results show that the Mains sensor provides sufficiently accurate and reliable information for improving the awareness of energy consumption of a household.Langaton sähköpäätaulusensori kotitalouden energiankulutuksen seuraamiseen. Tiivistelmä. Tutkimusten mukaan tietoisuus energiankulutuksesta voi johtaa sähkön käytön vähenemiseen, ja että tosiaikainen, laitekohtainen kulutustieto olisi hyödyllisempää. Silti nykyisin sähköyhtiöiden asiakkaiden täytyy tyypillisesti tyytyä kulutustietoihin, jotka on kerätty kokonaiskulutuksesta, ovat käytettävissä viiveellä, ja joihin on vaikea päästä käsiksi. Kattava tosiaikainen informaatio myös auttaisi huippukulutuskausien välttämisessä ja energiankulutuksen optimoinnissa dynaamisen hinnoittelun suhteen. Tämän diplomityön tavoitteena oli suunnitella ja valmistaa langaton sensori kotitalouden energiankulutuksen jatkuvaan ja tosiaikaiseen mittaukseen osana UBI-AMI-järjestelmän versiota 2. Syntynyt sähköpäätaulusensori lukee kokonaisenergiankulutuksen kilowattituntimittarista joko galvaanista tai optista yhteyttä käyttäen. Yksittäiset ryhmäkohtaiset kuormat mitataan sulaketaulusta Hallin antureilla. 8-bittinen mikrokontrolleri kerää analogiset mittaukset ja muuntaa ne digitaaliseksi dataksi, joka lähetetään UBI-AMI-järjestelmälle käyttäen kaupallista 6LoWPAN-radiomoduulia ja CoAP-protokollaa. Mittausdata mahdollistaa integroitujen ja kiinteästi asennettujen sähkölaitteiden, esimerkiksi lattialämmityksen ja saunan, energiankulutuksen eriyttämisen kotitalouden kokonaiskulutuksesta. Sähköpäätaulusensorin toiminta arvioitiin testilaitteistolla, joka koostui sulaketaulusta, kilowattituntimittarista ja pistorasioista kuormien liittämistä varten. Sähköpäätaulusensorin havaittiin lukevan kokonaisenergiankulutuksen kilowattituntimittarista virheettömästi galvaanista yhteyttä käyttäen. Optista yhteyttä käytettäessä sensori kykeni lukemaan 84 % nopeista pulsseista ja hitaat pulssit saivat sensorin mittaamaan käytetyn energian 4% todellista suuremmaksi. Hallin antureilla suurin keskimääräinen virhe kaupalliseen mittariin verrattuna oli 0,47 % pätötehollisella kuormalla. Tulosten perusteella sähköpäätaulusensori antaa riittävän tarkkaa ja luotettavaa tietoa energiankulutuksesta ja sitä voidaan käyttää energiankulutuksen tietoisuuden lisäämiseen kotitalouksissa

    Monitoring wireless sensor network nodes with a low intrusion hybrid monitor

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    [EN] This work presents an active hybrid monitor with low intrusion, to be applied on sensor network nodes. Intrusion caused to the sensor node has been evaluated on three aspects: time, additional code, and power consumption.[ES] Se presenta un monitor híbrido activo de baja intrusión, aplicable a nodos de redes de sensores. La intrusión causada al nodo sensor ha sido evaluada en tres aspectos: tiempo, código adicional, y el consumo de energía.Navia Mendoza, MR. (2015). Monitoring wireless sensor network nodes with a low intrusion hybrid monitor. http://hdl.handle.net/10251/67823Archivo delegad
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