Poor air quality can greatly affect the public health. Research studies indicate that indoor air can be more polluted than the outdoor air. An indoor air quality monitoring system will help to create an awareness of the quality of air inside which will eventually help in improving it. The objective of this research is to develop a low cost wireless sensor system for indoor air quality monitoring. The major cost reduction of the system is achieved by using low priced sensors. Interface circuits had to be designed to make these sensors more accurate. The system is capable of measuring carbon dioxide, carbon monoxide, ozone, temperature, humidity and volatile organic compounds. The prototype sensor node modules were developed. The sensor nodes were the connected together by Zigbee network. The nodes were developed in such a way that it is compact in size and wireless connection of sensor nodes enable to collect air quality data from multiple locations simultaneously. The collected data was stored in a computer. We employed linear least-square approach for the calibration of each sensor to derive a conversion formula for converting the sensor readings to engineering units. The system was tested with different pollutants and data collected was compared with a professional grade monitoring system for analyzing its performance. The results indicated that the data from our system matched quite well with the professional grade monitoring system.

The Internet was initially built around networks based on physical cables, the next step to improve the accessibility of the Internet came with the introduction of wireless communication. the next step to improving accessibility to the Internet came with the introduction of wireless communication. Because the IoT products are wirelessly connected, they need an internal power source in the form of a battery. Many of the existing communication protocols are therefore not suitable for IoT solutions because they are power consuming. Alternatives to these communication protocols have therefore been developed, for example LTE-M, NB-IoT and LoRaWAN. The study was conducted in cooperation with Etteplan. Etteplan want to invest in LoRaWAN and thus want to gain deeper knowledge within LoRaWAN. Thus, it was chosen to investigate how different factors affect the signal strength transmission time in a LoRaWAN. The focus of the study has thus been on the communication between an IoT node and a receiver in a LoRaWAN, thus the purpose of the study: To show how different data rates, distances and environments affect the quality of information sent from an IoT node to a receiver in LoRaWAN. Design science research was used as a research method, in design science research an artefact is constructed and then studied. In this study, a LoRaWAN was constructed and the communication between an IoT node and receiver in this LoRaWAN was studied. To study the communication between the IoT node and the receiver, two experiments were performed. The experiments were performed simultaneously where the difference was in the data collected, one experiment collected the signal strength and the second the transmission time. The experiment was conducted in two different environments, one with a clear view and one with blockages. In the experiment, the IoT node was positioned at different distances with different data rates. The result of the study shows how different data rates, distances and environments affected the quality of information between an IoT node and receiver and how they relate to previous research. Data rate was the factor that affected the quality of the information most. Data rate had minimal impact on signal strength, but great impact on number of lost data packet and transmission times. The two different environments had no effect on the transmission time, but the signal strength was over 10 dbm lower in the urban environment than with clear view. The distance had no effect on transmission time and minimal impact on signal strength. / Internet var i begynnelsen uppbyggt kring nätverk baserade på fysiska kablar, nästa steg för att förbättra tillgängligheten till Internet kom med introduktionen av trådlös kommunikation. Ett nytt begrepp dök upp vid millennieskiftet, Internet of Things (IoT). Tanken bakom IoT är att olika typer av produkter, som exempelvis tandborstar och kylskåp trådlöst kopplas upp mot Internet. Eftersom IoT-produkterna är trådlöst uppkopplade behöver de en intern strömkälla i form av ett batteri. Många av de existerande kommunikationsprotokollen lämpar sig därför inte för IoT-lösningar eftersom dessa är strömkrävande. Alternativ till dessa kommunikationsprotokoll har därför tagits fram, till exempel LTE-M, NB-IoT och LoRaWAN. Studien utfördes i samarbete med Etteplan. Etteplan vill satsa på LoRaWAN och vill därmed få en djupare kunskap inom LoRaWAN. Därmed valdes det att undersöka hur olika faktorer påverkar signalstyrkan och sändningstiden i ett LoRaWAN. Studiens fokus har därmed varit på kommunikationen mellan en IoT-nod och en mottagare i ett LoRaWAN, därmed är studiens syfte: Att visa på hur olika datahastigheter, avstånd och miljöer påverkar kvaliteten på informationen som sänds från en IoT-nod till en mottagare i ett LoRaWAN. Design science research användes som forskningsmetod då i design science research konstrueras en artefakt som att sedan undersöks. I studiens fall konstruerades ett LoRaWAN där sedan kommunikationen mellan en IoT-nod och mottagare i detta LoRaWAN studerades. För att studera kommunikationen mellan en IoT-nod och en mottagare utfördes två experiment. Experimenten utfördes samtidigt där skillnaden låg i datat som samlades in, det ena experimentet samlade in signalstyrkan och den andra sändningstiden. Experimentet utfördes i två olika miljöer, en med fri sikt och en med blockeringar. I experimentet positionerades IoT-noden på olika avstånd med olika datahastigheter. Resultatet från studien visar hur olika datahastigheter, avstånd och miljöer påverkade kvaliteten på informationen mellan en IoT-nod och mottagare och hur de relateras till tidigare forskning. Datahastigheten var den faktorn som påverkade kvaliteten på informationen mest. Datahastigheten hade minimal påverkan på signalstyrkan, men stor påverkan på antal förlorade datapaket och sändningstider. De två olika miljöerna hade ingen påverkan på sändningstiden, men signalstyrkan var över 10 dbm lägre i stadsmiljön än med fri sikt. Avståndet hade ingen påverkan på sändningstiden och minimal påverkan på signalstyrkan.

The aim of this paper is to study the different parts of a wireless system in order to better understand the signal properties and what key factors changes the signal during its transmission. Two transmitters were created, an FM transmitter that transmits analog data and an Arudino board programed to convert data to bits before its transmission. The acquired signals were then compared to the original signal noting how differently the data had changed. To understand the antennas contribution to the system a simulation was done using High Frequency Structural Simulator. A description of the analysis on the different acquired signals was done to determine the best applications they might have.

No description available.

The thesis deals with the design of a goniophotometer and the GUI (Graphical User Interface), capable of evaluating the photometric parameters of light sources and luminaires. The introduction contains theoretical information about photometry, photometric parameters, light sources, lamps, as well as the theory of measuring these parameters, and basic globally used data formats, designed to store the parameters of light sources. The core of this thesis, then describes the hardware, that makes up the proposed device, and the software needed to control the measurement process, visualization and storing the results. The conclusion is an evaluation of the functionality of the described device, and the measurements that were mediated by it, and an overall summary of the results achieved.

Submitted by Maike Costa (maiksebas@gmail.com) on 2016-05-03T13:34:32Z No. of bitstreams: 1 arquivo total.pdf: 3707373 bytes, checksum: bd34d34553cf7afe6f47457ea76d0a05 (MD5) / Made available in DSpace on 2016-05-03T13:34:32Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 3707373 bytes, checksum: bd34d34553cf7afe6f47457ea76d0a05 (MD5) Previous issue date: 2014-03-06 / Commercial flame photometers require a dedicated gas system and have considerable mass and volume, i. e., they are not portable. This work, as such, proposes the development of a portable flame photometer (prototype) using a torch lighter as the atomizer and controller, with an internal gas supply system, and managed by an Android mobile device. The internal control of prototype and the signal processing were performed by an Arduino Uno single-board microcontroller. The Android application was developed in App Inventor, an open source integrated development environment created and maintained by Massachusetts Institute of Technology. The nebulization was accomplished by ultrasonic cavitation in an adapted low power humidifier, which produces an aerosol sample which consists of very small radii droplets. The initiallyturbulent aerosol flow, needed to be damped before it reached the flame. Initial testswith calibration solutions of K+ resulted in a calibration curve validated using analysis of variance, the limits of detection and quantification were estimated. Optimizations still need to be made in the nebulization and aerosol transport system to improve theefficiency and to minimize inter-contamination of samples during the measurements. / Os fotômetros de chama comerciais necessitam de um sistema de gases dedicado e possuem massa e volume consideráveis, ou seja, não são portáteis. O presente trabalho, diante do exposto, propõe-se a mostrar o desenvolvimento de um protótipo de fotômetro de chama portátil pelo uso de um isqueiro maçarico como atomizador, com sistema de alimentação de gases interno e gerenciado por um dispositivo móvel Android. O controle interno do protótipo bem como o processamento de sinal foram realizados por um Arduino Uno. Um aplicativo para o dispositivo móvel foi desenvolvido no App Inventor, ambiente de programação criado e mantido pelo Instituto de Tecnologia de Massachusetts. A nebulização se deu por cavitação ultrassônica em um humidificador de baixa potência o qual produz um aerossol de amostra constituído por gotículas de raio muito pequeno. O fluxo de aerossol inicialmente turbulento precisou ser amortecido antes de sua introdução no queimador. Testes iniciais com soluções de calibração de K+ resultaram numa curva analítica validada utilizando-se a Análise de Variância e os limites de detecção e de quantificação foram determinados. No entanto otimizações ainda precisam ser feitas no sistema de nebulização e transporte de aerossol para a melhoria de sua eficiência e para a minimização de intercontaminação de amostras durante as medidas.

This bachelor thesis at the Royal Institute of Technology in Stockholm, Sweden, aims to clarify how the minimum bandwidth of a stabilised mobile inverted pendulum is affected by the position of its center of mass and the frequency of measuring the state variables. The scope is to apply basic theories in automation control and electronic systems when designing the system. The mechatronical system in the experimental trials is constructed with the main components consisting of bipolar stepper motors, stepper motor drivers (DRV8825), potentiometer and Arduino UNO. The mobile pendulum in question consists of a cart on a rail with a potentiomoter and a rod mounted to it. In the experimental trials in this paper, three different radial positions of the center of mass are analysed with regards to the bandwidth of relevant measurements. A variety of PID parameters, for both the angle and position regulation, are the essential basis on which these stability trials are performed. The results are limited to the resolution of the potentiometer outputs, the length of the rail and the stiffness of the rod. The result is presented by comparisons between data of the greatest angles which are stabilised and the corresponding maximal latency of the angle corrections. These data concludes to that the minimum required bandwidth to sustain stability decreases for an increasing length between the center of mass and the point of rotation. / Denna kandidatexamensuppsats genomfördes på Kungliga Tekniska Högskolan, i Stockholm, Sverige, och har som mål att klargöra hur den minsta bandbredden för en stabiliserad inverterad pendel påverkas av positionen av dess tyngdpunkt samt nätfrekvensen av tillståndsvariablerna. Projektet omfattar grundläggande teorier om reglerteknik och elektriska system.  Det mekatroniska systemet som används i experimenten är uppbyggt av följande nyckelkomponenter: bipolära stegmotorer, stegmotordrivare (DRV8825), potentionmeter och Arduino UNO. Den mobila pendeln består av en stång och en potentiometer som är monterad på en vagn löpandes på en räls. I de utförda experimenten i denna rapport analyseras tre radiella positioner på masscentrum med hänsyn till bandbredden och relevanta mätningar. En reglering med olika PID parametrar, för både vinkel- och positionsreglering, är den kritiska process som lade grunden för analyserna av stabiliteten. Resultaten är begränsade av upplösningen hos potentiometerns utsignal, längden av rälsen och stångens styvhet.  Resultaten presenteras genom jämförelser mellan data för de största vinklarna som stabiliseras och de motsvarande maximala fördröjningarna. Sammanfattningsvis minskar den minst nödvändiga bandbredden för att upprätthålla stabilitet för ökande längder mellan pendelns tyngdpunkt och rotationspunkten.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This paper presents the obtaining of electric power consumption curves, from the responses generated by an embedded low-cost Raspberry Pi 2 Model B system running the Linux operating system Raspbian working as a remote access server SSH, which is assessed through different types of access and brute force attacks dictionaries through specialized tools Medusa and Hydra, as well as the tool Metasploit unspecialized. The energy behavior is interpreted by a current consumption measurement system developed by low embedded platform cost Arduino Uno that runs a current sensor based on ACS721ELC-5A Hall effect chip, which has the ability to collect the variations generated by the platform test in response to events produced by the proposed test scenarios, the data is processed by the framework Matlab that collects, parses and normalizes using the Welch method, the current signal which is interpreted by Arduino Uno subsequently presents a standard curve It features a particular event based on scenarios of evidence. The results show the different curves standard patterns, and contextualized on the types of scenarios evaluated subsequently presents a theoretical mathematical model of the proposed power consumption, as well as rules or signatures proposed to identify an attack using the detection method of standards used IDS Snort. These current curves facilitate understanding and obtaining a pattern of current consumption for each access and attack the embedded platform. / Este trabalho apresenta a obtenção de curvas de consumo de corrente elétrica, a partir das respostas geradas por um sistema embarcado de baixo custo Raspberry Pi 2 Model B executando o sistema operacional Linux Raspbian trabalhando como um servidor de acesso remoto SSH, que é avaliado através de diferentes tipos de acessos e ataques de força bruta com dicionários através das ferramentas especializadas Medusa e Hydra, como também a ferramenta não especializada Metasploit. O comportamento energético é interpretado por um sistema de medição de consumo de corrente desenvolvido pela plataforma embarcada de baixo custo Arduino Uno que administra um sensor de corrente baseado no chip ACS721ELC- 5A de efeito Hall, que possui a capacidade de coletar as variações geradas pela plataforma de teste em resposta aos eventos produzidos pelos cenários de provas propostos, os dados são processados pelo Framework Matlab que coleta, analisa e normaliza por meio do método de Welch o sinal de corrente que é interpretado pelo Arduino Uno, posteriormente apresentase uma curva padrão que caracteriza um determinado evento baseado nos cenários de provas. Os resultados apresentam as diferentes curvas padrões normalizadas, e contextualizadas nos tipos de cenários avaliados, seguidamente apresenta-se um modelo matemático teórico do consumo de corrente proposto, como também as regras ou assinaturas propostas para identificar um ataque através do método de detecção por padrões que utilizada o IDS Snort. Essas curvas de corrente facilitam o entendimento e obtenção de um padrão de consumo de corrente para cada acesso e ataque na plataforma embarcada.

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 diploma thesis deals with wattmeters. The introduction is devoted to approach the issue. Subsequently, the principle of sensing of circumferential quantities, sampling theory and basic theory is explained. The next chapter discusses Arduino development kits. The practical part deals with the design of the circuit diagram and the printed circuit board. Further described is designed software. The final part tests the parameters of the designed power meter.