Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 5 Articles
Wireless sensor networks (WSNs) require an extremely energy-efficient design. As sensor nodes have limited power\r\nsources, the problem of autonomy is crucial. Energy harvesting provides a potential solution to this problem.\r\nHowever, as current energy harvesters produce only a small amount of energy and their storage capacity is limited,\r\nefficient power management techniques must also be considered. In this article we address the problem of modeling\r\nand simulating energy harvesting WSN nodes with efficient power management policies. We propose furthermore a\r\nframework that permits to describe and simulate an energy harvesting sensor node by using a high level modeling\r\napproach based on power consumption and energy harvesting. The node architectural parameters as well as the\r\non-line power management techniques will also be specified. Two new power management architectures will be\r\nintroduced, taking into account energy-neutral and negative-energy conditions. Simulations results show that the\r\nthroughput of a sensor node can be improved up to 50% when compared to a state of the art power management\r\nalgorithm for solar harvesting WSN. The simulation framework is then used to find an efficient system sizing for a solar\r\nenergy harvesting WSN node....
The dependability deficiencies and bandwidth constraints of the controller area network (CAN) can prevent its use in\r\nsafety-relevant and performance-demanding applications. This paper introduces mechanisms for fault detection and\r\nfault isolation based on an intelligent CAN router, which exploits a priori knowledge about the permitted behavior of\r\nattached electronic control units (ECUs) in order to detect and contain failures. Experiments using an FPGA-based\r\nimplementation of the CAN router evaluate these mechanisms under different failure modes (e.g., timing failures,\r\nmasquerading failures). Due to its compatibility to the CAN standard, the router can improve the dependability and\r\nperformance of systems with existing ECUs. In addition, we extend the application areas of CAN to systems with\r\nhigher performance and dependability requirements than can be supported with a conventional bus-based network...
As technology scales for increased circuit density and performance, the management of power consumption in\r\nembedded systems is becoming critical. Because the operating system (OS) is a basic component of the embedded\r\nsystem, the reduction and characterization of its energy consumption is a main challenge for the designers. In this\r\nwork, a flow of low power OS energy characterization is introduced. The variation of the energy and power\r\nconsumption of the embedded OS services is studied. The remainder of this article details the methods used to\r\ndetermine energy and power overheads of a set of basic services of the embedded OS: scheduling, context switch\r\nand inter-process communication. The impacts of hardware and software parameters like processor frequency and\r\nscheduling policy on the energy consumption are analyzed. Also, models and laws of the power and energy are\r\nextracted. Then, to quantify the low power OS energetic overhead, the obtained models are integrated in the system\r\nlevel design. Our method allows estimating the energy consumption of the low power OS services when running an\r\napplication on a specific hardware platform....
The interest of physiological data sensing and recording using wireless body sensor network has increased in\r\nrecent years due to the advancement of miniature and portable electronic devices. In this study, the design of a\r\nportable and rechargeable data logger with high data rate multiple wireless connectivity (Bluetooth and 2.4-GHz\r\nradio frequency) is discussed. The data are logged in micro secure digital (SD) cards and can be transferred to PC or\r\nSmartphone using SD card reader, USB interface, or Bluetooth wireless link. Analog signals can also be logged\r\nthrough an 8-channel analog-to-digital interface. A graphical LCD with touch screen is added for control and\r\ndiagnosis. The hardware is generic and targeted for various medical imaging and data collection applications. The\r\nfunctionality of the prototype is later tested for wireless capsule endoscopy and skin temperature logging\r\napplication....
This project is designed to develop a Wireless Electronic Notice Board. It is widely used to display latest information anywhere such as faculty, shop, mosque and other places. This Wireless Electronic Notice Board offers the flexibility to user to control the information display within 25m range. The information is transmitted using RF as wireless technique. The Wireless Electronic Notice Board consists of two module; transmitter and receiver module. There are five parts in transmitter module and four parts in receiver module. In transmitter module, there are keypad, Liquid Crystal Display (LCD), Microcontroller, encoder and transmitter. In receiver module there are receiver, decoder, microcontroller, and dot matrix. This project is based on AT89c51 microcontroller. Assembly language is used to program the microcontroller....
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