Microcontroller platforms are heavily used in embedded solutions adopted in nearly every industry covering a wide range of applications and use cases. In the paper and pulp industry the change prompted by the rising popularity of data decentralisation, big data analysis and machine learning, forces companies to upgrade or renew old platforms used to collect and analyse data. This thesis will evaluate a generation change for a communication platform that collects data from a sensor, its capabilities regarding secure communication over TCP/IP with the possibility to implement an efficient machine-to-machine communication protocol. The main focus of the evaluation is development, implementation and integration of software for the embedded system with a real time operating system using the ARM Cortex M7. Using small open source tools and the powerful ARM core we were able to build a small, flexible, real time system that publishes sensor data over MQTT securely using TCP/IP and TLS.

É crescente, nos últimos anos, a utilização da tecnologia de orientação a objetos para a construção de sistemas complexos. A aceitação de que tal tecnologia, alem de facilitar a modularização e proporcionar maior reusabilidade, permitindo uma visão unificada dos sistemas, tem encorajado sua utilização na construção de sistemas operacionais, onde recursos do sistema e aplicações do usuário passam a ser modelados em termos da mesma abstração. Na realidade, esta nova tecnologia de desenvolvimento de software, aliada a evolução do hardware, da tecnologia de comunicações e a necessidade de um incremento qualitativo, principalmente no que diz respeito a ambientes de programação e interfaces, está provocando o surgimento de uma nova geração de sistemas operacionais, mais dinâmicos, mais flexíveis e capazes de suportar de forma transparente a presença de processamento cooperativo, distribuído ou não, heterogêneo ou não. Todavia, ainda que a literatura científica demonstre a aceitação do paradigma de orientação a objetos como um enfoque promissor a ser adotado na nova geração de sistemas operacionais, o estado atual da tecnologia de implementação e gerenciamento de objetos esta aquém da consolidação. Este trabalho surgiu neste contexto com o objetivo de contribuir na busca de um modelo apropriado ao gerenciamento de objetos e capaz de proporcionar a existência de um modelo uniforme, tanto para o nível do sistema operacional como para o nível da aplicação. O resultado da pesquisa desenvolvida foi o surgimento de um modelo estrutural orientado a objetos e baseado nas idéias da reflexão computacional, não somente como disciplina de implementação, mas como modelo conceitual para a implementação de sistemas operacionais multiprocessados. / The use of object-oriented technology for the construction of complex systems has been increasing in recent years. The assumption that such technology, besides facilitating modularization, increases reusability and maintainability, providing a unified view of the systems, has encouraged its use in building operating systems, where the system resources and the user's applications come to be modeled in terms of the same abstraction. Actually this new technology for development of software, associated with the evolution of hardware, as well as communication technology and the need for qualitative enhancement, mainly concerning programming and interface environments, is giving rise to a new generation of operating systems, more dynamic, more flexible and capable of maintaining, in a transparent way, the presence of cooperative processing, distributed or non-distributed, heterogeneous or homogeneous. However, although the scientific literature shows an acceptance of the object-oriented paradigm as a promising focus(insight) to be adopted in the new generation of operating systems, the current state of technology for object management is still far from being one of consolidation. This project has emerged in this context, with the aim of contributing to the search for an appropriate model for office management that is able to provide a uniform model, not only on the operating system level, but also on the application level. The result of the research is a new object-oriented structural model, based on the concepts of computational reflection, both as an implementation discipline and as a conceptual model for the utilization of multiprocessor operating systems. These features are very useful in developing operating systems which contain components, including resources and applications that are modeled in the same way, using object-oriented abstraction.

É crescente, nos últimos anos, a utilização da tecnologia de orientação a objetos para a construção de sistemas complexos. A aceitação de que tal tecnologia, alem de facilitar a modularização e proporcionar maior reusabilidade, permitindo uma visão unificada dos sistemas, tem encorajado sua utilização na construção de sistemas operacionais, onde recursos do sistema e aplicações do usuário passam a ser modelados em termos da mesma abstração. Na realidade, esta nova tecnologia de desenvolvimento de software, aliada a evolução do hardware, da tecnologia de comunicações e a necessidade de um incremento qualitativo, principalmente no que diz respeito a ambientes de programação e interfaces, está provocando o surgimento de uma nova geração de sistemas operacionais, mais dinâmicos, mais flexíveis e capazes de suportar de forma transparente a presença de processamento cooperativo, distribuído ou não, heterogêneo ou não. Todavia, ainda que a literatura científica demonstre a aceitação do paradigma de orientação a objetos como um enfoque promissor a ser adotado na nova geração de sistemas operacionais, o estado atual da tecnologia de implementação e gerenciamento de objetos esta aquém da consolidação. Este trabalho surgiu neste contexto com o objetivo de contribuir na busca de um modelo apropriado ao gerenciamento de objetos e capaz de proporcionar a existência de um modelo uniforme, tanto para o nível do sistema operacional como para o nível da aplicação. O resultado da pesquisa desenvolvida foi o surgimento de um modelo estrutural orientado a objetos e baseado nas idéias da reflexão computacional, não somente como disciplina de implementação, mas como modelo conceitual para a implementação de sistemas operacionais multiprocessados. / The use of object-oriented technology for the construction of complex systems has been increasing in recent years. The assumption that such technology, besides facilitating modularization, increases reusability and maintainability, providing a unified view of the systems, has encouraged its use in building operating systems, where the system resources and the user's applications come to be modeled in terms of the same abstraction. Actually this new technology for development of software, associated with the evolution of hardware, as well as communication technology and the need for qualitative enhancement, mainly concerning programming and interface environments, is giving rise to a new generation of operating systems, more dynamic, more flexible and capable of maintaining, in a transparent way, the presence of cooperative processing, distributed or non-distributed, heterogeneous or homogeneous. However, although the scientific literature shows an acceptance of the object-oriented paradigm as a promising focus(insight) to be adopted in the new generation of operating systems, the current state of technology for object management is still far from being one of consolidation. This project has emerged in this context, with the aim of contributing to the search for an appropriate model for office management that is able to provide a uniform model, not only on the operating system level, but also on the application level. The result of the research is a new object-oriented structural model, based on the concepts of computational reflection, both as an implementation discipline and as a conceptual model for the utilization of multiprocessor operating systems. These features are very useful in developing operating systems which contain components, including resources and applications that are modeled in the same way, using object-oriented abstraction.

É crescente, nos últimos anos, a utilização da tecnologia de orientação a objetos para a construção de sistemas complexos. A aceitação de que tal tecnologia, alem de facilitar a modularização e proporcionar maior reusabilidade, permitindo uma visão unificada dos sistemas, tem encorajado sua utilização na construção de sistemas operacionais, onde recursos do sistema e aplicações do usuário passam a ser modelados em termos da mesma abstração. Na realidade, esta nova tecnologia de desenvolvimento de software, aliada a evolução do hardware, da tecnologia de comunicações e a necessidade de um incremento qualitativo, principalmente no que diz respeito a ambientes de programação e interfaces, está provocando o surgimento de uma nova geração de sistemas operacionais, mais dinâmicos, mais flexíveis e capazes de suportar de forma transparente a presença de processamento cooperativo, distribuído ou não, heterogêneo ou não. Todavia, ainda que a literatura científica demonstre a aceitação do paradigma de orientação a objetos como um enfoque promissor a ser adotado na nova geração de sistemas operacionais, o estado atual da tecnologia de implementação e gerenciamento de objetos esta aquém da consolidação. Este trabalho surgiu neste contexto com o objetivo de contribuir na busca de um modelo apropriado ao gerenciamento de objetos e capaz de proporcionar a existência de um modelo uniforme, tanto para o nível do sistema operacional como para o nível da aplicação. O resultado da pesquisa desenvolvida foi o surgimento de um modelo estrutural orientado a objetos e baseado nas idéias da reflexão computacional, não somente como disciplina de implementação, mas como modelo conceitual para a implementação de sistemas operacionais multiprocessados. / The use of object-oriented technology for the construction of complex systems has been increasing in recent years. The assumption that such technology, besides facilitating modularization, increases reusability and maintainability, providing a unified view of the systems, has encouraged its use in building operating systems, where the system resources and the user's applications come to be modeled in terms of the same abstraction. Actually this new technology for development of software, associated with the evolution of hardware, as well as communication technology and the need for qualitative enhancement, mainly concerning programming and interface environments, is giving rise to a new generation of operating systems, more dynamic, more flexible and capable of maintaining, in a transparent way, the presence of cooperative processing, distributed or non-distributed, heterogeneous or homogeneous. However, although the scientific literature shows an acceptance of the object-oriented paradigm as a promising focus(insight) to be adopted in the new generation of operating systems, the current state of technology for object management is still far from being one of consolidation. This project has emerged in this context, with the aim of contributing to the search for an appropriate model for office management that is able to provide a uniform model, not only on the operating system level, but also on the application level. The result of the research is a new object-oriented structural model, based on the concepts of computational reflection, both as an implementation discipline and as a conceptual model for the utilization of multiprocessor operating systems. These features are very useful in developing operating systems which contain components, including resources and applications that are modeled in the same way, using object-oriented abstraction.

CubeSat projects in various universities around the world have become predominant in the study and research for developing CubeSats. Such projects have broadened the scope for understanding this new area of space research. Different CubeSats have been developed by other universities and institutions for different applications. The process of design, development and deployment of CubeSats involves several stages of theoretical and practical work ranging from understanding the concepts associated with communication subsystems, data handling subsystems to innovations in the field like implementing compatible operating systems in the CubeSat processors and new designs of transceivers and other components. One of the future trend setting research areas in CubeSat projects is the implementation of ROS in CubeSat. Robot Operating System (ROS) is aiming to capture the future of many embedded systems including Robotics. In this thesis, an attempt is made to understand the challenges faced during implementing ROS in CubeSat to provide a foundation for the OBDH subsystem and provide important guidelines for future developers relying on ROS run CubeSats. Since using traditional transceivers and power supply would be expensive, we have tried simulating Arduino to act as transceiver and power supply subsystems. Arduino is an open-source physical computing platform based on a simple microcontroller board, and a development environment for writing software for the board designed to make the process of using electronics in major embedded projects more accessible and inexpensive. Another important focus in this thesis has been to establish communication between CubeSat kit and Arduino. The major motivating factor for this thesis was to experiment with and come up with alternate ways which could prove as important measures in future to develop an effective and useful CubeSat by cutting down on development costs. An extensive literature review is carried out on the concepts of Arduino boards and ROS and its uses in Robotics which served as a base to understand its use in CubeSat. Experiment is conducted to communicate the CubeSat kit with Arduino. The results from the study of ROS and experiments with Arduino have been highly useful in drafting major problems and complications that developers would encounter while implementing ROS in CubeSat. Comprehensive analysis to the results obtained serve as important suggestions and guidelines for future researchers working in this field. / One of the future trend setting research areas in CubeSat projects is the implementation of ROS in CubeSat. Robot Operating System (ROS) is aiming to capture the future of many embedded systems including Robotics. In this thesis, an attempt is made to understand the challenges faced during implementing ROS in CubeSat to provide a foundation for the OBDH subsystem and provide important guidelines for future developers relying on ROS run CubeSats. Since using traditional transceivers and power supply would be expensive, we have tried simulating Arduino to act as transceiver and power supply subsystems. Arduino is an open-source physical computing platform based on a simple microcontroller board, and a development environment for writing software for the board designed to make the process of using electronics in major embedded projects more accessible and inexpensive.

This thesis presents an evaluation of the Solaris version of the Xen virtual machine monitor and a comparison of its performance to the performance of Solaris Containers under similar conditions. Xen is a virtual machine monitor, based on the paravirtualization approach, which provides an instruction set different to the native machine environment and therefore requires modifications to the guest operating systems. Solaris Zones is an operating system-level virtualization technology that is part of the Solaris OS. Furthermore, we provide a basic performance evaluation of the security modules for Xen and Zones, known as sHype and Solaris Trusted Extensions, respectively. We evaluate the control domain (know as Domain-0) and the user domain performance as the number of user domains increases. Testing Domain-0 with an increasing number of user domains allows us to evaluate how much overhead virtual operating systems impose in the idle state and how their number influences the overall system performance. Testing one user domain and increasing the number of idle domains allows us to evaluate how the number of domains influences operating system performance. Testing concurrently loaded increasing numbers of user domains we investigate total system efficiency and load balancing dependent on the number of running systems. System performance was limited by CPU, memory, and hard drive characteristics. In the case of CPU-bound tests Xen exhibited performance close to the performance of Zones and to the native Solaris performance, loosing 2-3% due to the virtualization overhead. In case of memory-bound and hard drive-bound tests Xen showed 5 to 10 times worse performance.

This thesis investigates how different Linux-distributions installation interface relate to the ISO 9241 standard, parts 12 and 13, and how they relate to the installation interface of Windows XP, with the hypothesis: "There is a Linux-distribution whose installation interface according to applicable HCIrecommendations is equivalent to that of Windows XP." With the checklists provided by ISO 9241 an empirical study has been made, and so comparable measurements of how well the Linux-distributions and Windows XP follows the recommendations of the standard was obtained. By comparing the results from the tests similarities and differences between the installation interfaces can be deducted. As the result and the conclusion shows there are Linux-distributions whose installation interface, according to the applicable HCI-recommendations, are equivalent to that of Windows XP.

A key step when initiating robot powered production is setting up the control software.This can be a threshold for operators, especially if the software is fragmented and system requirements are extensive.One way to address this is to pre-configure all the control programs and bundle them with a system that fulfills all the requirements. In this work a live operating system (OS) is loaded with control software and configured to  meet the needs of those who have just assembled their first 3D printer.The problem of downloading, configuring and installing various 3D printer controlling programs  is reduced to the problem of distributing and booting the live OS. The solution of loading it onto bootable USB drives is tested and evaluated in the context of a commercial RepRap Assembly Workshop (RAW),  an event where people pay for RepRap 3D printer parts as well as assembly and usage supervision.The RAW is unusually short, so the bootable USB drives' potential to help  RAW hosts with particularly tight time schemes is tested. The results show a limited success.The USB drive is documented not to work for 3 participant groups out of a total of 11 groups.As a solution to fragmented software and diverse system requirements, the live OS is found to work well once booted.Several routes to make the live OS more easily bootable are discussed. Usage examples beyond drop-in replacing existing RAW software setup procedures are discussed. / Alla som startar upp robotiserad produktion måste få igång och börja använda styrprogramvaran.Detta kan inebära en hög tröskel för operatörer, specielt om programen är många och har olika gränssnitt och systemkrav.Ett sätt att hjälpa operatörerna komma igång är att konfigurera alla styrprogram på förhand  och bunta ihop dem med ett system som uppfyller alla krav. I detta arbetet laddas ett live operativsystem med styrprogramvara och konfigureras för att lätt kunna  användas av någon som precis har satt ihop sin första 3D-skrivare.Problemen med hemladdning, konfigurering och installation av en rad olika styrprogram  reduceras till problemet att distribuera och boota live operativsystemet. Lösningen att lasta live-systemet på startbara (eng. bootable) USB-minnen testas och utvärderas  som en del av en kommersiell RepRap monteringskurs (eng. RepRap Assembly Workshop),  ett event där deltagare betalar för RepRap 3D-skrivardelar,  hjälp med att montera ihop dem och med att använda de färdiga 3D-skrivarna.Den undersökta monteringskursen är ovanligt kort, så startbara USB-minnens potential att  underlätta för tidsprässade kursvärdar testas. Resultaten visar en begränsad framgång.Vi visar hur 3 av 11 deltagargrupper inte lyckas använda de startbara USB-minnena.Som en lösning på fragmenterad mjukvara med stora systemkrav fungerar live operativsystemet bra när det väl har startats.Olika sätt att göra live-systemet lättare att starta diskuteras. Tillämpningsområden utöver att ersätta existerande programuppsättslösningar för RepRap monteringskurser diskuteras.

There are several timing mechanisms on presently available commercial operating systems. Two operating system platforms that immediately come to mind are the Microsoft Windows environment (the WIN32 platform) and its UNIX-based counterpart, Linux (with its POSIX standard). The timing mechanisms under these operating systems are adequate for use in conventional multimedia applications currently run on these platforms. However, the requirements of such applications are not as stringent within a real-time environment. The goal of this dissertation was to determine if it would be possible to find a workaround for applications where current timing mechanisms in the WIN32 and POSIX environments do not meet the requirements of real-time. Before a proposed workaround is presented, a clarification is given as to what is meant by the notion of a timer. Attention is also given to the fact that its accuracy is quantified in terms of its resolution. It is acknowledged that real-time extensions to both the Windows and Linux operating systems exist. However, it was decided to find a solution without such assistance. Real-time is also defined and sub-classified into hard- and soft real-time, differentiating environments that have precise constraints (hard real-time) on timing as opposed to environments where demands on accuracy and efficiency are less stringent (soft real-time). The timer that was ultimately implemented had to conform to the latter form of real-time. This dissertation therefore aims to provide a solution in a soft real-time environment. The current timing mechanisms are discussed and their performance is quantified. Their deficiency in measuring a reliable periodic interval of 1 ms is highlighted. From this qualification of timers stems the requirements for the soft real-timer timer. The areas in which improvement is sought are stated. The design and implementation of a soft real-time timer that meets these requirements is presented and its performance at various frequencies is quantified. A comparison is given between the timer and the existing timing mechanisms as well as comparison between its implementation under both Windows and Linux. Additionally, the viability of the proposed timer compared to a proven hard real-time timer is presented. Finally it is recognised that a timer would not be useful if it was not effective in a practical environment. Consequently, the timer’s performance under the same load that it would experience in a practical soft real-time environment is investigated as well. The dissertation concludes with a discussion on the compatibility of this timer with expected advances in future Central Processing Unit (CPU) technologies. / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / MSc / unrestricted

No description available.