1,488 research outputs found

    The Design and Implementation of an Extensible Brain-Computer Interface

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    An implantable brain computer interface: BCI) includes tissue interface hardware, signal conditioning circuitry, analog-to-digital conversion: ADC) circuitry and some sort of computing hardware to discriminate desired waveforms from noise. Within an experimental paradigm the tissue interface and ADC hardware will rarely change. Recent literature suggests it is often the specific implementation of waveform discrimination that can limit the usefulness and lifespan of a particular BCI design. If the discrimination techniques are implemented in on-board software, experimenters gain a level of flexibility not currently available in published designs. To this end, I have developed a firmware library to acquire data sampled from an ADC, discriminate the signal for desired waveforms employing a user-defined function, and perform arbitrary tasks. I then used this design to develop an embedded BCI built upon the popular Texas Instruments MSP430 microcontroller platform. This system can operate on multiple channels simultaneously and is not fundamentally limited in the number of channels that can be processed. The resulting system represents a viable platform that can ease the design, development and use of BCI devices for a variety of applications

    Towards an optical wireless communication based Vehicle to Vehicle Communication System

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    Vehicle to Vehicle (V2V) Communication is a developing technology that aims to make road transportation systems intelligent, to avoid accidents and traffic congestions. This thesis presents Optical Wireless Communication (OWC) as a solution that will drive the next generation of V2V systems. The current standards for V2V and vehicle to infrastructure (V2I) communication, based on radio frequency techniques, are revised. Also, the current standard for Visible Light Communication (VLC), IEEE 802.15.7 is analyzed. This project also shows the first steps towards a cost-effective implementation of V2V VLC taking advantage of already available hardware in vehicles. Finally, a transmission system is presented aiming to demonstrate an adaptation of current VLC standards for V2V and V2I communication. Another system based on IR communication is also presented. These are presented as an alternative for V2V and V2I solutions based on radio frequency techniques, opening the door to a relevant industrial application of optical wireless communication

    Humidifier with a web interface control

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    PFC del programa Erasmus EPS elaborat a Instituto Superior de Engenharia do PortoTreball desenvolupat dins el marc del programa 'European Project Semester'.In the text we will show how tomake a humidifier with a web interface control. The goal of our project is to keep under full control the humidity level of a 80 m³ server room. We will go through, step by step, from choosingthetype of humidifier,itcontrol,andtheweb interfacewe are planning to buildup

    dsPIC-based signal processing techniques and an IT-enabled distributed system for intelligent process monitoring and management

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    dsPIC Technology employs a powerful 16-bit architecture into single-chip devices that seamlessly integrate the diverse attributes of a microcontroller with the computation and throughput capabilities of a digital signal processor in a single core. The key element of this dissertation is to explore how dsPIC has influenced the applicability of research in e-Monitoring systems. At the same time dsPIC has offered the opportunity to develop methodologies which were previously not even considered. The dsPIC devices are used, in this research, for front end data acquisition, signal processing and communication tools within a proposed monitoring architecture. In this work, novel digital signal processing (DSP) techniques are developed for the monitoring of an example application, namely the challenging one of tool breakage in milling operations. The monitoring regime is implemented on the dsPIC and its capabilities for real-time frequency analysis using overlap FFT and Multiband IIR Filters with dynamic coefficient selection techniques is explored. The developed systems are tested for various cutting conditions using existing machine tool signals and tool breakage is detected reliably in real-time. In attempting to enhance the accuracy of tool monitoring it is evident that the depth of cut (DOC) is an important parameter and achieving its on-line monitoring provides valuable information for condition monitoring. A systematic approach is adopted for the analysis and selection of ultrasonic sensors for distance measurement. A DOC monitoring system is developed using the dsPIC as the data acquisition and processing core. To achieve reliable results, various DSP algorithms are developed, implemented and verified for their effectiveness. The system integration stage combines the above elements for robust and reliable decision making and provides communication of the generated information to support management function using the internet and GSM connectivity. This integration enables an enhanced process management system which is capable of identifying all significant events, for offline analysis and subsequent diagnosis in addition to the real time diagnostic mode

    Tutorial: A Versatile Bio-Inspired System for Processing and Transmission of Muscular Information

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    Device wearability and operating time are trending topics in recent state-of-art works on surface ElectroMyoGraphic (sEMG) muscle monitoring. No optimal trade-off, able to concurrently address several problems of the acquisition system like robustness, miniaturization, versatility, and power efficiency, has yet been found. In this tutorial we present a solution to most of these issues, embedding in a single device both an sEMG acquisition channel, with our custom event-driven hardware feature extraction technique (named Average Threshold Crossing), and a digital part, which includes a microcontroller unit, for (optionally) sEMG sampling and processing, and a Bluetooth communication, for wireless data transmission. The knowledge acquired by the research group brought to an accurate selection of each single component, resulting in a very efficient prototype, with a comfortable final size (57.8mm x 25.2mm x 22.1mm) and a consistent signal-to-noise ratio of the acquired sEMG (higher than 15 dB). Furthermore, a precise design of the firmware has been performed, handling both signal acquisition and Bluetooth transmission concurrently, thanks to a FreeRTOS custom implementation. In particular, the system adapts to both sEMG and ATC transmission, with an application throughput up to 2 kB s-1 and an average operating time of 80 h (for high resolution sEMG sampling), relaxable to 8Bs-1 throughput and about 230 h operating time (considering a 110mAh battery), in case of ATC acquisition only. Here we share our experience over the years in designing wearable systems for the sEMG detection, specifying in detail how our event-driven approach could benefit the device development phases. Some previous basic knowledge about biosignal acquisition, electronic circuits and programming would certainly ease the repeatability of this tutorial

    Układ do Generowania Efektów Dźwiękowych

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    Mestrado em Engenharia Electrónica e TelecomunicaçõesO objectivo principal da presente tese de mestrado centrou-se no desenho e construção de uma unidade de efeitos de áudio (Audio Effects Unit -AEU), cuja função consiste em processar sinais áudio em tempo real. O propósito central foi desenvolver uma unidade de processamento áudio genérica, cuja função de processamento, implementada no domínio digital, pode ser facilmente especificada pelo utilizador via uma aplicação de software implementada num computador. A primeira etapa deste projecto consistiu na implementação completa do hardware que constitui o AEU. É importante acrescentar que esta concepção teve em conta a inclusão desse hardware numa caixa apropriada. Este método de projecto e implementação constituiu uma experiência muito interessante e útil. A próxima etapa consistiu no desenvolvimento de algoritmos matemáticos a ser implementados no microcontrolador do AEU e que geram os efeitos sonoros desejados por processamento dos sinais áudio originais. Estes algoritmos foram inicialmente testados através do Matlab. Para controlar os efeitos sonoros produzidos foi ainda criada uma aplicação de computador que permite a intervenção, de forma muito simples, do utilizador. A referida aplicação assegura a comunicação entre o microcontrolador do AEU e o computador através de uma ligação USB. O dispositivo, na sua versão final, foi testado em laboratório e através do Matlab. Cada bloco do dispositivo, e o dispositivo completo, foi testado individualmente. Com base nessa avaliação foram desenhadas as respectivas características na frequência e analisada a qualidade do dispositivo de áudio. Para além da experiência adquirida em concepção de hardware, este projecto permitiu-me alargar o meu conhecimento em programação de microcontroladores e na optimização de código, um requisito do processamento de sinal em tempo real. Também me deu a oportunidade de utilizar a ferramenta comercial MPLAB para programação de microcontroladores.The main aim of this master thesis was to design and build an Audio Effects Unit (AEU), whose function is to process, a particular audio signal in real time. The objective was to develop a general purpose audio processing unit where the processing function, implemented in the digital domain, can be easily specified by the user by means of a software application running on a computer. The first stage of this project consisted on the full design and implementation of the hardware that constitutes the AEU. It is worth adding that such design also considered that the layout could be placed in an enclosure. Such way of designing was a great new experience. The next stage was to prepare the mathematical algorithms to be implemented in the AEU microcontroller which create the sound effects by processing the original audio signal. These algorithms were first tested in MatLab. To control the produced sound effects a computer program was created which allows the user intervention in a straightforward way. This program ensures communication between the AEU microcontroller and PC software using an USB connection. The completed device was tested in laboratory and with Matlab. The individual blocks of the AEU, and the whole device, were tested. On the basis of these tests frequency characteristics were drawn and the quality of the audio device was analyzed. Besides acquiring expertise in hardware design, this project has broadened my knowledge on microcontroller programming and code optimization, a requirement for real time signal processing. It also gave me the opportunity to use the commercial MPLAB programming environment.Głównym celem tej pracy magisterskiej było zaprojektowanie i zbudowanie układu do generowania efektów dźwiękowych (Audio Effects Unit - AEU) służącego do przetwarzania sygnału dźwiękowego w czasie rzeczywistym. Zadaniem autora było skonstruowanie ogólnego zastosowania układu przetwarzającego sygnał dźwiękowy, w którym funkcja przetwarzania, zaimplementowana w sposób cyfrowy, może być łatwo określona przez użytkownika poprzez zastosowanie odpowiedniego oprogramowania komputerowego. Pierwszy etap projektu polegał na szczegółowym zaprojektowaniu i zbudowaniu warstwy sprzętowej tworzącej AEU. W projekcie przewidziano tez możliwość umieszczenia układu w obudowie, co było dla autora nowym doświadczeniem projektowym. Kolejnym etapem było opracowanie algorytmów matematycznych, zaimplementowanych w mikrokontrolerze AEU, które tworzą efekty dźwiękowe poprzez przetwarzanie oryginalnego sygnału dźwiękowego. Te algorytmy zostały najpierw przetestowane w programie MatLab. Do kontrolowania wytworzonych efektów dźwiękowych, został napisany program komputerowy, który pozwala na prostą interakcje z użytkownikiem. Ten program zapewnia komunikację między mikrokontrolerem AEU i oprogramowaniem komputerowym poprzez złącze USB. Gotowe urządzenie zostało zbadane w laboratorium oraz za pomocą programu Matlab. Poszczególne bloki AEU jak i całe urządzenie zostały przetestowane, co pozwoliło na wykreślenie charakterystyk częstotliwościowych i umożliwiło analizę jakości wykonanego urządzenia audio. Oprócz zdobywania doświadczenia w projektowaniu sprzętu, udział w projekcie poszerzył moją wiedzę o programowaniu mikrokontrolerów i optymalizacji kodu, potrzebną dla przetwarzania sygnału w czasie rzeczywistym. Ponadto miałem możliwość zapoznania się z komercyjnym środowiskiem programistycznym MPLAB

    Proactive Indoor Air Quality Monitoring System

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    In recent times indoor air quality has attracted the attention of policy makers and researchers similar to that of external air pollution. The indoor environments are confined and closed compared to external environments providing less opportunity for the pollutants to dilute. Our everyday devices emit various solids and gases into the environment during their operation. These emissions contain many substances that are harmful to human health, when exposed to them for a prolonged period of time. Here we propose an air quality monitoring system that allows us to monitor and check live air quality in particular areas through IOT. The System uses air sensors to sense presence of harmful gases/compounds in the air and constantly transmit this data to microcontroller PIC16F877A. The sensors interact with microcontroller which processes this data and transmits it over internet. The gas levels can be viewed through a webpage from anywhere in the world. This allows authorities to monitor air pollution in different areas and take action against it
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