FlexRay is a deterministic communication bus in the automotive context that supports fault-tolerant and high-speed bus system. It operates based on the time-division-multiple-access scheme and allows transmission of event-driven and time-driven messages between nodes in a system. A FlexRay bus has two periodic segments which form a bus cycle: static segment and dynamic segment. Such a bus system could be used in a wide area of real-time automotive applications with soft and hard timing constraints. Recent research has been focused on the FlexRay static segment. As opposed to the static segment, however, the dynamic one is based on an event-triggered scheme. This scheme is more difficult to be temporally predicted. Nevertheless, the event-triggered paradigm provides more flexibility for further incremental design. The dynamic segment is also suitable for applications with erratic data size. Such advantages motivate for more research on the dynamic segment. In a real-time system, results of the computations have to be ready by a specific instant of time called deadline . However, in a soft real-time application, the result can be used with a degraded Quality of Service even after the deadline has passed while in a hard real-time system, missing a deadline leads to a catastrophe. This thesis aims at optimizing some of the parameters of the FlexRay bus for soft real-time applications. The cost function which helps to assess the solution to the optimization problem is the deadline miss ratio and a solution to our problem consists of two parts: (1) Frame identifiers to messages which are produced at each node. (2) The size of each individual minislot which is one of the FlexRay bus parameters. The optimization is done based on genetic algorithms. To evaluate the proposed approach, several experiments have been conducted based on the FlexRay bus simulator implemented in this thesis. The achieved results show that suitable choice of the parameters which are generated by our optimization engine improves the timing behavior of simulated communicating nodes.

A humidity sensor can be used to measure the moisture content of the environment. The physical change of the sensor expresses as the change of electrical property like capacitance, resistance, voltage, current, frequency, etc. In order to process these analog signals digitally, microprocessor is involved in the measurement. This thesis presents design of a circuit to measure low moisture levels. The 16-bit RISC mixed signal microcontroller MSP430F249 from Texas Instruments will be used. The circuit has good performance at extremely low humidity levels. Meanwhile, a small real time operating system kernel FreeRTOS, a market leading RTOS from Real Time Engineer Ltd is ported to the microcontroller. The basic concept about FreeRTOS and how to port this RTOS to MSP430F249 microcontrollers will be the topics of this thesis as well.

We first propose a reconfigurable processor, which consists of a MicroBlaze processor augmented with a Field-Programmable Gate Array (FPGA) to mitigate the computing time for public-key cryptography algorithms. We first consider Virtex-II Pro from Xilinx to analyze the potential solution of a Field-Programmable Custom Computing Machine (FCCM), which is composed of MicroBlaze augmented with a Virtex-II FPGA. We then propose a cryptography-oriented reconfigurable array, called CryptoRA, that efficiently supports long-word integer addition, subtraction and comparison. As a result, RISC processor can potentially be augmented with the CryptoRA rather than Virtex-II. The three main features that CryptoRA has are: (i) an increased granularity of the logic tile, (ii) the extension of the dedicated carry chain over the horizontal direction, and (iii) the incremental splitting Look-Up Table. According to our simulations, the CryptoRA-based FCCM provides a significant performance improvement over an optimized pure-software solution at an acceptable cost.

For the reliability design of Engine Control Unit devices in motor vehicles, the knowledge of stresses occurring in the field within the product service life is essential. In addition to the environmental influences such as temperature, moisture and humidity, vibration and shock issues are in focus. To ensure the robustness of the products and they are still easily and inexpensively made, they must be interpreted appropriately in the development process. For this, the load spectra for the mechanical influences of road conditions and operating conditions are to be determined. Work will also include temperature and humidity values examined on typical installation locations. The essential everyday situations (commuters, taxi, farmer, ...) should be considered. Existing measurement technology must be combined to this end a comprehensive logger system with communication to the vehicle.

Sistemas embarcados, em especial aqueles utilizados em robótica, apresentam, em sua estrutura, uma multiplicidade de dispositivos que resultam em uma arquitetura bastante heterogênea e bem distribuída. Para auxiliar na resolução dessa complexidade inerente, este trabalho resgata os conceitos de frameworks, buscando na sua integração e modelo conceitual, desenvolver um conjunto de ferramentas que gerencia a mediação entre sistemas embarcados e demais aplicações de software, fornecendo bibliotecas e componentes reutilizáveis para aplicações na robótica. Propõe-se utilizar framework e middleware de sistemas open-source para integração entre a plataforma de software e hardware. Um dos objetivos do projeto é criar um framework multi-plataforma com diferentes tipos de serviços para o de desenvolvimento de aplicações no campo da robótica. O projeto tem como estudo de caso sistemas embarcados aplicados em robótica móvel e tecnologia assistiva. / Embedded systems, especially those used in robotics, present in its structure, a plurality of devices that result in a very heterogeneous and well distributed architecture. To help resolve this inherent complexity, the work rescues the concepts of frameworks, seeking their integration and conceptual model, develop a set of tools that manage to mediate between embedded systems and other of software applications, providing reusable libraries and components for applications in robotics. It is proposed to use framework and middleware systems open source for integration between the platform software and hardware. One of the project objectives is to create a multi-platform framework with different types of services, considering the programming and compatibility with hardware for the development of applications in the field of robotics. The project’s case study developing embedded applied in mobile and Assistive Technology robotics.

Sistemas embarcados, em especial aqueles utilizados em robótica, apresentam, em sua estrutura, uma multiplicidade de dispositivos que resultam em uma arquitetura bastante heterogênea e bem distribuída. Para auxiliar na resolução dessa complexidade inerente, este trabalho resgata os conceitos de frameworks, buscando na sua integração e modelo conceitual, desenvolver um conjunto de ferramentas que gerencia a mediação entre sistemas embarcados e demais aplicações de software, fornecendo bibliotecas e componentes reutilizáveis para aplicações na robótica. Propõe-se utilizar framework e middleware de sistemas open-source para integração entre a plataforma de software e hardware. Um dos objetivos do projeto é criar um framework multi-plataforma com diferentes tipos de serviços para o de desenvolvimento de aplicações no campo da robótica. O projeto tem como estudo de caso sistemas embarcados aplicados em robótica móvel e tecnologia assistiva. / Embedded systems, especially those used in robotics, present in its structure, a plurality of devices that result in a very heterogeneous and well distributed architecture. To help resolve this inherent complexity, the work rescues the concepts of frameworks, seeking their integration and conceptual model, develop a set of tools that manage to mediate between embedded systems and other of software applications, providing reusable libraries and components for applications in robotics. It is proposed to use framework and middleware systems open source for integration between the platform software and hardware. One of the project objectives is to create a multi-platform framework with different types of services, considering the programming and compatibility with hardware for the development of applications in the field of robotics. The project’s case study developing embedded applied in mobile and Assistive Technology robotics.

The recent increase in performance of embedded processors has enabled the use of computationally heavy asymmetric cryptography in small and power efficient embedded systems. The goal of this thesis is to analyze whether it is possible to use this type of cryptography to enhance the security in access systems. This report contains a literature study of the complications related to access systems and their functionality. Also a basic introduction to cryptography is included. Several cryptographic algorithms were implemented using the public library LibTomCrypt and benchmarked on an ARM7-processor platform. The asymmetric coding schemes were ECC and RSA. The tested symmetric algorithms included AES, 3DES and Twofish among others. The benchmark considered both codesize and speed of the algorithms. The two asymmetric algorithms, ECC and RSA, are possible to be used in an ARM7 based access system. Although, both technologies can be configured to finish the calculations within a reasonable time-frame of 10 Sec, ECC archives a higher security level for the same execution time. Therefore, an implementation of ECC would be preferable since it is faster and requires less resources. Some further suggestions of improvements to the implementation is discussed in the final chapters.

Com a evolução tecnológica há nos dias de hoje um aumento de dispositivos eletrônicos presentes ao nosso redor. Com o passar dos anos diversas funcionalidades vêm sendo agregadas a estes inclusive com maior poder de processamento. Em particular, para sistemas embarcados houve um crescimento da quantidade de sensores para diversos propósitos. Seguindo esta tendência, na área de saúde também houve um aumento significativo de aparelhos e dispositivos de monitoramento, tais como glicosimetros, oxímetros, monitoramento de pressão e batimento cardíaco por exemplo, que através de sensores realizam transdução dos dados pertinentes ao parâmetro envolvido. Este trabalho apresenta a pesquisa e o desenvolvimento de um sistema embarcado com a propriedade de multiplexação de sensores, ou seja, foi desenvolvido um dispositivo microcontrolado o qual visa multiplicar a capacidade de monitoramento de analitos, conseguindo analisar múltiplos sensores para um mesmo experimento. Ao decorrer deste desenvolvimento foram utilizados quatro sensores dispostos simetricamente em um béquer, os dados são coletados e tratados de forma sequencial e individual. Inicialmente utilizamos um sistema embarcado com um microcontrolador (PIC 18F2550) que é responsável por digitalizar a informação e pela conexão via terminal USB. Posteriormente um microprocessador (Raspberry Pi Zero, placa embarcada) fez-se necessário devido ao melhor processamento de dados. Os sensores aqui estudados tratam-se de sensores químicos, que são introduzidos a uma célula eletroquímica, onde se encontram um eletrodo de referência (Prata em uma solução de Cloreto de Prata) e os outros quatro filmes finos que irão compor o sistema multiplexado. Para este estudo em específico o material escolhido para fabricação dos filmes finos foi um polímero condutivo, mais especificamente polianilina (PANI). Esta foi depositada sobre um substrato de oxido de estanho dopado com flúor (FTO) através da eletrodeposição. Para sensores não específicos (não imobilizados para um analito alvo) os dois sistemas embarcados apresentaram respostas satisfatórias. Prosseguindo com o estudo e usando filmes finos para analitos biológicos (ureia e glicose) o microcontrolador não conseguiu separar os sinais de cada filme fino. Apenas o sistema com a Raspberry Pi obteve sucesso, devido a maior resolução no conversor analógico para digital e sua maior capacidade de processamento para determinar com uma maior precisão os valores obtidos. O sistema pode ser facilmente expandido para um maior número de sensores. / With the evolution of technology there is nowadays an increase in the number of electronic devices present around us. Over the years various functionalities have been added to these devices including the increased processing power. In particular, for embedded systems there has been an increase in the number of sensors for various purposes. Following this trend, in the area of health, there has also been a significant increase in systems and monitoring devices, such as glycosimeters, oximeters, pressure monitoring and heart rate, for example, which, through sensors, transduce data pertinent to the parameter involved. This work presents the research and development of an embedded system with the property of multiplexing sensors, that is, a microcontrolled device was developed which aims to multiply the capacity of analytes monitoring, being able to analyze multiple sensors for the same experiment. During this development four sensors were used symmetrically arranged in a beaker, the data were collected and treated sequentially and individually. Initially we used an embedded system with a microcontroller (PIC 18F2550) that is responsible for scanning the information and for the connection via USB terminal. Subsequently a microprocessor (Raspberry Pi Zero, embedded board) was made necessary due to the better processing of data. The sensors studied here are chemical sensors, which are introduced to an electrochemical cell, where a reference electrode is found (Silver in a Silver Chloride solution) and the other four thin films that will make up the multiplexed system. For this specific study the material chosen for the manufacture of thin films was a conductive polymer, more specifically polyaniline (PANI). This was deposited on a substrate of fluorine-doped tin oxide (FTO) by electrodeposition. For non-specific sensors (not immobilized for a target analyte) the two embedded systems presented satisfactory responses. Proceeding with the study and using thin films for biological analytes (urea and glucose) the microcontroller failed to separate the signals from each thin film. Only the system with Raspberry Pi has been successful, due to the higher resolution in the analog to digital converter and its greater processing capacity to determine with greater precision the obtained values. The system can be easily expanded to a larger number of sensors.

Sistemas embarcados, em especial aqueles utilizados em robótica, apresentam, em sua estrutura, uma multiplicidade de dispositivos que resultam em uma arquitetura bastante heterogênea e bem distribuída. Para auxiliar na resolução dessa complexidade inerente, este trabalho resgata os conceitos de frameworks, buscando na sua integração e modelo conceitual, desenvolver um conjunto de ferramentas que gerencia a mediação entre sistemas embarcados e demais aplicações de software, fornecendo bibliotecas e componentes reutilizáveis para aplicações na robótica. Propõe-se utilizar framework e middleware de sistemas open-source para integração entre a plataforma de software e hardware. Um dos objetivos do projeto é criar um framework multi-plataforma com diferentes tipos de serviços para o de desenvolvimento de aplicações no campo da robótica. O projeto tem como estudo de caso sistemas embarcados aplicados em robótica móvel e tecnologia assistiva. / Embedded systems, especially those used in robotics, present in its structure, a plurality of devices that result in a very heterogeneous and well distributed architecture. To help resolve this inherent complexity, the work rescues the concepts of frameworks, seeking their integration and conceptual model, develop a set of tools that manage to mediate between embedded systems and other of software applications, providing reusable libraries and components for applications in robotics. It is proposed to use framework and middleware systems open source for integration between the platform software and hardware. One of the project objectives is to create a multi-platform framework with different types of services, considering the programming and compatibility with hardware for the development of applications in the field of robotics. The project’s case study developing embedded applied in mobile and Assistive Technology robotics.

Este trabalho apresenta o projeto de uma portadora que opera na frequência de 8.300 MHz para ser utilizado em moduladores vetoriais diretos com aplicação em sistemas embarcados de satélites. Foram realizados estudos sistêmicos de arquiteturas que operam nesta faixa de frequência com as características necessárias para atender as especificações da European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation da agência espacial europeia -ESA, que regulamenta as frequências e características para sistemas de transmissão para enlace de descida. A partir dos conhecimentos adquiridos nos estudos, é apresentada uma metodologia de projeto visando o atendimento das especificações definidas pela ECSS e a escolha de uma topologia de projeto. Foram realizadas simulações a nível sistêmico, utilizando o software Advanced Design System-ADS da fabricante Keysight Technologies, para definir as especificações de projeto dos circuitos que compõem o sistema de geração da portadora na banda X. O circuito da malha de sincronismo de fase - PLL opera na frequência de 2.075 MHz, onde seu sinal é amplificado e filtrado pela cadeia de amplificação na banda S cuja função é aumentar a isolação para minimizar os efeitos de pulling do oscilador controlado por tensão - VCO, devido à alta velocidade nas transições de tempo de subida e de descida dos sinais digitais I e Q. O filtro também é responsável por aumentar a rejeição de espúrios e harmônicos gerados pelos efeitos não lineares dos amplificadores. O sinal é enviado ao circuito multiplicador de frequências que gera o sinal na banda X e é filtrado por um filtro passa-faixas de linhas acopladas, rejeitando os sinais espúrios provenientes da saída do multiplicador de frequência. Na saída, o sinal passa por uma cadeia de amplificação na banda X para adequar o nível de potência à entrada dos moduladores vetoriais. Os circuitos projetados foram desenvolvidos utilizando tecnologia de microfita de linha. Os protótipos foram caracterizados, apresentando boa concordância com os resultados simulados, comprovando experimentalmente a metodologia de projeto utilizada neste trabalho assim como o atendimento das especificações sugeridas pela ECSS. / This work presents the project of an carrier that works in the frequency of 8,300 MHz to be used in direct vector modulator for embedded system application in satellites. It were realized system level studies of PLL topologies that work in this frequency range with the necessary features to provide the requirements from European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation of the European Space Agency - ESA, which is responsible for the frequencies and features regulation for downlink transmission system. With the knowledge acquired from the studies, it is presented a project method intending to the meet the requirements defined by the ECSS and the definition of a topology to the project. It were performed system level simulation, using the Advanced Design System - ADS tool, from Keysight Technologies, in order to define the design specifications in the project of the circuits of the X band carrier generator developed. The PLL circuit works in the frequency of 2,075 MHz, in which its signal is amplified and filtered for amplifier chain in S band, increasing the isolation to reduce the pulling effects in the voltage controlled oscillator, due to the high-speed transitions in the rise time and fall time of the digital signal I and Q. The filter is also responsible for increasing the rejection of spurious and harmonics generated by non-linear amplifiers effects. The signal is conducted to the frequency multiplier circuit that generates the X band signal and it is filtered by a coupled line bandpass filter, rejecting the spurious from the frequency multiplier output. At the output stage, the signal passes through a X band amplification chain in order to adequate the power level of the vector modulators input level. The specified circuits were designed and developed using microstrip line technology. The prototypes were characterized, presenting adequate results according to the data obtained by the simulations, experimentally reinforcing the project method used in this work as well as the meeting of the requirements suggested by the ECSS.