Η διπλωματική εργασία αυτή αφορά την κατασκευή ενός μικροϋπολογιστικού συστήματος διαχωρισμού σημάτων. Ο διαχωρισμός των σημάτων γίνεται με βάση τη θεωρία της τεχνικής της Ανάλυσης Ανεξάρτητων Συνιστωσών. Αφού παρουσιαστεί η θεωρία της τεχνικής, παρουσιάζεται ο μικροελεγκτής ADuC 7026 που επελέγη για την υλοποίηση. Στη συνέχεια γίνεται η παρουσίαση του λογισμικού προσομοίωσης του μικροελεγκτή και παρατίθενται βασικά παραδείγματα για τον προγραμματισμό του. Τέλος, αναπτύσσονται, χωρίς τη χρήση περιφερειακών, και προσομοιώνονται, με τη χρήση περιφερειακών τρεις αλγόριθμοι, δυο εκδόσεις του FastICA και μια έκδοση του InfoMax. Οι αλγόριθμοι αυτοί αξιολογούνται ως προς τις επιδόσεις τους και εξάγονται τα συμπεράσματα. / This thesis deals with the construction of a microcomputer system to separate signals. The separation of the signals is based on the theory of the technique of Independent Component Analysis. The theory of the technique and the microcontroller ADuC 7026 chosen for implementation are presented. Then, follows the presentation of the software on which the microcontroller is simulated and basic examples of its programming are mentioned. Finally, three algorithms, two versions of FastICA and a version of InfoMax, are developed without the use of peripheral systems and simulated using peripheral systems. These algorithms are evaluated for their performance and conclusions are drawn.

Un nœud d'un réseau de capteurs sans fil traite dans ses unités de calcul les signaux issus de plusieurs types de capteurs et effectue différentes tâches liées aux protocoles de communication. Devant exécuter plusieurs types de contrôle, sa flexibilité est un paramètre très important. Les solutions à base de microcontrôleurs ou de FPGA ont été proposées pour aborder le besoin de flexibilité, mais au prix d'une efficacité énergétique réduite. Dans cette thèse, des contrôleurs flexibles à ultra-faible énergie basés sur un contexte de micro-tâches reconfigurables sont explorés comme alternative. Des architectures modulaires pour des machines d'états finis (FSM) et des chemins de données (DP) reconfigurables sont proposées. Les techniques de coupure de l'alimentation (PG pour power gating) sont utilisées pour adapter la consommation aux besoins et réduire la puissance statique. Dans un premier temps, des modèles pour l'estimation des paramètres clés d'un circuit avec PG sont proposés au niveau porte. Ensuite, les opportunités des techniques PG sont déterminées sur les FSM et DP reconfigurables pour en réduire l'énergie. Dans les chemins de données, la reconfiguration fait varier la précision des opérateurs et le PG permet d'éteindre les blocs logiques inutilisés. Une gestion de l'alimentation au niveau lookup table (LUT) est proposée pour réduire les courants de fuite en mode actif et en veille dans les FSM reconfigurables. Des résultats montrent les très bonnes performances des architectures proposées par rapport aux processeurs et FPGA. / A wireless sensor network (WSN) node may need to process signals from various sensors and perform different transceiver tasks apart from being able to change its functions dynamically. A controller in the node is therefore required to execute different control tasks to manage its resources implying that flexibility is a key concern. Microcontrollers and FPGAs have been proposed to address the need for flexibility at the cost of reduced energy efficiency. In this thesis, ultra-low power flexible controllers for WSN nodes based on reconfigurable microtasks are explored. A reconfigurable microtask is a digital control unit with a reconfigurable finite state machine (FSM) and datapath. Scalable architectures for reconfigurable FSMs along with variable precision adders in datapath are proposed for flexible controllers in this work. Power gating is considered for FSMs and adders for low power operation. First, the design issues in power gating are studied extensively. Models for estimation of key design parameters of power-gated circuits are derived at gate level. Next, power gating opportunities are determined in reconfigurable adders and FSMs proposed for microtasks. In adders, reconfigurability is used for varying the precision of operation and saving energy by power-gating unused logic. Power gating at the level of lookup table logic is proposed to achieve active leakage power reduction in reconfigurable FSMs. The proposed models are then applied to analyze energy savings in logic clusters due to power gating. Power estimation results show good performance of proposed architectures with respect to different metrics relative to others in the design space of controllers.

Made available in DSpace on 2016-12-23T14:07:26Z (GMT). No. of bitstreams: 1 Alexandre Secchin de Melo - parte 1.pdf: 1376671 bytes, checksum: 7504ac977143d6adfd9ac0c7c2bc0d2f (MD5) Previous issue date: 2010-06-30 / Este trabalho visa a implementação de um objeto voador não-tripulado, em formato miniatura, com quatro rotores como plataforma de desenvolvimento, como parte de uma pesquisa mais abrangente. O objetivo final, ainda por ser alcançado, é chegar a um veículo voador miniatura com o máximo grau de autonomia de decisões baseadas no sensoreamento a bordo e poder computacional embarcados, estratégia do controle inteligente, e tarefa a cumprir. Tal implemetação, até o momento, consiste em uma máquina eletro-mecânica de baixo custo, cuja parte eletrônica a bordo, um microcontrolador de 8 bits, acelerômetros e giroscópios do tipo MEMS, permite a implementação de um controlador de voo genérico para automatizar a sua estabilização em torno dos eixos X, Y e Z. Tem vasta gama de aplicações como: inspeções aéreas em diversos ambientes, como linhas de transmissão elétrica, detecção de foragidos da polícia, monitoramento de plantações e rebanhos, bem como tomadas de filmagens para as indústrias cinematográfica e imobiliária. Testes realizados com o protótipo até agora sugerem a implementação bem sucedida de um controlador de estabilização de voo / This work aims the implementation of a unmanned, four-rotor miniature flying machine as a development platform, part of a long term research. The final goal, yet to be achieved, is the realization of a flying object with maximum practicable degree of autonomous decisions based on the on-board sensory and computational power, control strategy and assigned task. Up to this work, it consists of a low cost electro-mechanical hardware, whose electronic part allows the implementation of an 8-bit microcontroller-based, MEMS accelerometer and gyroscopes, allows the implementation of a generic fly control for attitude stabilization. The broad spectrum of applications includes: the inspection of various kinds of environments such as electric power transmission lines, police surveillance of woods and hard-to-reach places with sky sight for fugitive detection, crops and herd monitoring, as well as film takings for the cinematographic and real estate industries. Tests undertaking so far with the prototype suggest the successful implementation of a fly attitude controller

Denna rapport handlar om utveckling av ett undervisningsmaterial för elever på fordonsprogrammet inom området elektroniska styrsystem. Rapporten beskriver processen från idé fram till färdigt undervisningsmaterial. Detta har tagits fram för att ge eleverna en bredare, mer generell kunskap inom detta ämnesområde än vad som är möjligt att få genom enbart teoretisk undervisning kring utvalda märkesspecifika system.  Undervisningsmaterialet bygger på teoretiska avsnitt som varvas med praktiska övningar kring en mikrokontroller med tillhörande sensorer och aktuatorer. Genom att skapa korta styrprogram som hanterar dessa sensorer kan olika funktioner skapas med hjälp av mikrokontrollen. Detta gör att många av de delfunktioner som används inom fordonselektroniska styrsystem kan simuleras.

Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη, προσομοίωση και κατασκευή διάταξης διασύνδεσης φωτοβολταϊκών συστημάτων δύο βαθμίδων με το δίκτυο της χαμηλής τάσης. Αντικείμενο της εργασίας ήταν η πρώτη βαθμίδα που αναλαμβάνει την ανύψωσης της τάσης, που δίνει στην έξοδο ένα φωτοβολταϊκό πλαίσιο, με σκοπό να συνδεθεί στην επόμενη βαθμίδα, όπου γίνεται η αντιστροφή της τάσης. Το κύκλωμα που μελετήθηκε είναι ένας μετατροπέας ανύψωσης και σταθεροποίησης της τάσης εξόδου και επιλέχθηκε από τη σειρά των μετατροπέων Luo. Συγκεκριμένα έπειτα από μελέτη των τοπολογιών και με βάση τις προδιαγραφές που είχαμε στη παρούσα εργασία έγινε η επιλογή δύο διατάξεων ως οι πιο κατάλληλες για την εφαρμογή. Η διάταξη Re-lift ανύψωσης τάσης και το στοιχειώδες κύκλωμα Υπέρ-Ανύψωσης Τάσης μελετήθηκαν θεωρητικά και έγινε προσομοίωση της λειτουργίας τους με πραγματικά στοιχεία. Με βάση τα αποτελέσματα που λήφθηκαν έγινε σύγκριση των δύο μετατροπέων και επιλέχθηκε η μία εκ των δύο για κατασκευή. Τελικά στο εργαστήριο κατασκευάστηκε το στοιχειώδες κύκλωμα Υπέρ-Ανύψωσης Τάσης και ο έλεγχος της διάταξης έγινε με τη χρήση μικροελεγκτή (dsPIC30F4011). Τα πειραματικά αποτελέσματα επιβεβαίωσαν την θεωρητική ανάλυση που έγινε και την ορθή λειτουργία του κυκλώματος. Ο βαθμός απόδοσης που προέκυψε στις πειραματικές μετρήσεις θεωρείται μάλλον χαμηλός της τάξης του 80% για την εφαρμογή αυτή, καθώς αποτελεί την πρώτη βαθμίδα σε σύστημα δύο βαθμίδων. Η συμπεριφορά όμως και το κέρδος τάσης είναι ικανοποιητικά για εφαρμογές χαμηλής ισχύος. / The present diplomatic work deals with the study, simulation and manufacture of a device for the connection of photovoltaic systems of two stages with the network of low voltage. Object of the work was the first stage that undertakes the elevation of voltage; we receive at the output of a photovoltaic panel, so as to connect it with the next stage, where the voltage is inverted. The circuit that was studied is a converter of elevation and stabilisation of the output voltage was selected from the Luo converters. In particular, after studying the topologies and taking into account the specifications that we had in the present work, two topologies were chosen as the most suitable for the application. The Re-lift converter and the elementary circuit of the superlift converters were studied theoretically and their operation was simulated with real elements. Based on the results that were taken, the two converters were compared and was selected which one of the two to manufacture. Finally the superlift elementary circuit was manufactured in the laboratory and the control of the circuit was done with the use of a microcontroller (dsPIC30F4011). The experimental results confirmed the theoretical analysis and the correct operation of the circuit. The degree of efficiency that resulted in the experimental measurements is considered rather low in the order of 80% for this application, while it constitutes the first stage in a system of two stages. The behaviour however and the voltage transfer gain are satisfactorily for applications of low power

Στην παρούσα διπλωματική εργασία, σχεδιάζονται και υλοποιούνται συστήματα με βάση τη πλατφόρμα του Arduino. Το πρώτο σύστημα αφορά ένα Wireless Persistence of Vision Display, ουσιαστικά μία οθόνη, σχήματος δίσκου, που αποτελείται από μία περιστρεφόμενη στήλη LEDs. Συνεχίζουμε με το σχεδιασμό ενός συστήματος ικανού για γρήγορη πρόβλεψη και ανακατασκευή σημάτων, με σκοπό τη μελλοντική χρήση του στο συγχρονισμό ενεργειακών δικτύων. Ύστερα προχωράμε στην υλοποίηση ενός συστήματος εντοπισμού διεύθυνσης πηγής ήχου, μέσα από την ψηφιακή επεξεργασία ηχητικών σημάτων. Τέλος, η εμπειρία που αποκομίσθηκε με βάση το Arduino μας οδήγησε στη μελέτη μιας εκπαιδευτικής πλατφόρμας βασισμένη σε FPGA, το «F-Penguino», που ως στόχο έχει να αναδείξει την ευελιξία και ταχύτητα συστημάτων βασισμένα σε υλοποίηση με περιγραφή υλικού / In this thesis, we design and implement various systems based on the Arduino platform. The first system is a Wireless Persistence of Vision Display, which is actually a round screen, made of a rotating column of LEDs. We also design a system capable of fast prediction and reconstruction of signals, with an utter goal, its future use in effectively connecting different power networks. Furthermore, we implement a sound source localization system, using DSP techniques and fundamental robotics. Finally, the experience obtained using the Arduino, led us to involve with an FPGA based platform, the “F-Penguino”, the goal of which is to indicate the versatility and speed of systems based on hardware-description implementations.

Ο βήχας είναι ένα κοινό σύμπτωμα σε πολλές ασθένειες του αναπνευστικού συστήματος. Αν και λειτουργεί ως προστατευτικός μηχανισμός απομάκρυνσης εκκρίσεων από την αναπνευστική οδό, η αυξημένη συχνότητα και έντασή του μπορεί να έχουν επίδραση στην ποιότητα ζωής του ασθενούς. Είναι το βασικότερο σύμπτωμα για το οποίο κάποιος επισκέπτεται τον γιατρό. Η σωστή εκτίμησή του είναι απαραίτητη τόσο για τον προσδιορισμό της αποτελεσματικότητας της θεραπείας αλλά και για την δοκιμή νέων θεραπειών και τη μελέτη των μηχανισμών του. Μέχρι στιγμής η διάγνωσή του βασίζεται σε υποκειμενικές καταγραφές, απλώς ζητώντας από τον ασθενή την εκτίμησή του για την ένταση, τη διάρκεια και τη συχνότητά του. Ένα σύστημα αυτόματης ανίχνευσης του σήματος του βήχα θα επέτρεπε την επικύρωση της παρουσίας και της συχνότητας του βήχα καθώς και την αποτελεσματικότητα της αγωγής. Τα συστήματα καταγραφής του βήχα δεν είναι καινούρια διαδικασία. Η πρώτη καταγραφή έγινε τη δεκαετία του '60 σε νοσηλευόμενους ασθενείς με τη χρήση μαγνητοφώνων και με χειροκίνητη καταγραφή των γεγονότων του βήχα. Στη συνέχεια με την εξέλιξη της τεχνολογίας κατασκευάστηκαν φορητές συσκευές που βασίστηκαν στην ταυτόχρονη καταγραφή ήχου και ηλεκτρομυογραφήματος (EMG σήματα, ανίχνευση κίνησης του θώρακα) για να ανιχνευθούν τα γεγονότα του βήχα όπου ακόμα τα σήματα έπρεπε να καταγραφούν και να μετρηθούν χειροκίνητα. Με τις παραπέρα ανακαλύψεις στις τεχνικές ψηφιακής καταγραφής, συμπίεσης και αποθήκευσης η διαδικασία αναγνώρισης και καταγραφής του βήχα μπορεί να αυτοματοποιηθεί με τη χρήση κατάλληλων αλγορίθμων. Στην εργασία αυτή κατασκευάζεται ένα ενσωματωμένο σύστημα καταγραφής, αποθήκευσης και επεξεργασίας του σήματος του βήχα. Για την επεξεργασία του αναπτύσσεται μια βασική μέθοδος βασισμένη την ενέργειά του. Στο πρώτο κεφάλαιο, γίνεται αναφορά στα χαρακτηριστικά του ηχητικού σήματος και παρατίθενται τα βασικά στάδια της ανάλυσής του. Στο δεύτερο, δίνεται ο ορισμός του βήχα, οι αιτίες που τον προκαλούν και η φυσιολογία του. Στη συνέχεια, παρουσιάζονται μέθοδοι για την ανίχνευσή του. Στο τρίτο κεφάλαιο, αναφέρονται οι βασικές έννοιες των μικροελεγκτών και παρατίθενται τα βασικά χαρακτηριστικά του μικροεπεξεργαστή ARM7TDMI, του μικροελεγκτή ADuC 7026 και της αναπτυξιακής πλατφόρμας μVision της Keil που χρησιμοποιήσαμε για την ανάπτυξη της εφαρμογής μας. Στο τελευταίο κεφάλαιο, παρουσιάζονται κάποιες λειτουργίες προγραμματισμού και δυνατότητες του μικροελεγκτή που χρησιμοποιούνται στην παρούσα εργασία. Στη συνέχεια αναπτύσσεται η εφαρμογή για την ανίχνευση του σήματος του βήχα. Στα παραρτήματα, παρατίθενται παραδείγματα για τον βασικό προγραμματισμό του ADuC 7026 και των περιφερειακών του. / Cough is a common symptom in many diseases of the respiratory system. Although cough protects humans by removing secretions through respiratory track, its increased frequency and intensity may impact on patient’s quality of life. Besides, cough is the main symptom that makes people to visit doctor. Doctor’s accurate assessment is necessary for determining treatment according to each patient as well as the testing of new treatments and the comprehensive study of cough. So far, the diagnosis of cough is based on subjective factors such as patient’s assessment of its intensity, duration and frequency. An automatic detection system of the cough signal would allow to determine about the presence and frequency of cough and an effective treatment. The attempt to record cough is not a new process. The first recording to patients was made in 60’s by the use of tape recorders and by manually recording the symptoms of cough. As technology has evolved, portable device was created that was based on simultaneous recording of sound and electromyography (EMG signals, detection of the movement of chest) in order to detect the symptoms of cough. In that case, the recording was also made manually. With the evolution of digital recording, compression and storage, the recognition and recording of cough can be automated by using the appropriate algorithms. In that study, an embedded system is made in order to record, store and process the signal of cough. A basic method based on energy is developed for the process. In the fisrt chapter, the characteristics of sound signal and the key stages of the analysis are presented. In the second chapter, cough is defined, its causes and the clinical symptoms of cough are analyzed. Then, methods for its detection are specified. In the third chapter, the basic concepts of microcontrollers are given as well as the main characteristics of microprocessor ARM7TDMI and of microcontroller ADuC 7026 are presented and the platform μVision of Keil that we used for the development of the application is analyzed. In the final chapter, some programming functions and properties of microcontroller are presented and are used for the current study. Then, the application of detection of cough signal is developed. In annex, examples for the basic programming of ADuC 7026 and its peripherals are given.

The present work was developed in the experimental area of the project "Pequeno Produtor, Grande Empreendedor that it is an area of vegetables production. It is located in the municipal district of Itabaiana in the state of Sergipe. The objective was to project and to create an automatized control of an irrigation system by leak, verifying the productive aspects related to the sustainability indicators. The calculation for water replacement in the soil was based on the estimate of the evapotranspiration starting from the reading of the climatological greatness accomplished by the agriculture-meteorological station installed at the experiment place. The equation of Penman-Montheith was used, recommended by the Food and Agricultural Organization of the United Nations (FAO). Once the estimated evapotranspiration was known, the control system did the other calculations to establish the time for the replacement of the necessary water sheet. The final comparison between the experiment and the normal production used by the producer points to a significant profit in the consumption of water and electric power. The microcontrolled control besides contributing for the decrease of the consumption of water supplies and electric power also provided an economy in the maintenance of the installed equipments. Doing so, a possibility of a higher economical profit is presented, contributing for life improvement of the small family producers, making their social and economic indicators better. / O presente trabalho foi desenvolvido na área experimental do projeto Pequeno Produtor Grande Empreendedor que é uma área de produção de hortaliças. Fica localizada no município de Itabaiana no estado de Sergipe. O objetivo foi projetar e criar um controle automatizado de um sistema de irrigação por gotejamento, verificando os aspectos produtivos relacionados com os indicadores de sustentabilidade. O cálculo para a reposição de água no solo foi baseado na estimativa da evapotranspiração a partir da leitura das grandezas climatológicas realizadas pela estação agro-meteorológica instalada no local do experimento. Utilizou-se a equação de Penman-Montheith, considerada padrão desde 1998 e recomendada pela Food and Agricultural Organization of the United Nations (FAO). Conhecida a evapotranspiração estimada, o sistema de controle realizou os demais cálculos para estabelecer o tempo necessário para a reposição da lâmina de água necessária. A comparação final entre o experimento e a produção normal utilizada pelo produtor aponta um ganho significativo no consumo de água e de energia elétrica. O controle microcontrolado além de contribuir para a diminuição do consumo dos recursos hídricos e energia elétrica, também proporcionou uma economia na manutenção dos equipamentos instalados. Com isso, chega-se a apresentar uma possibilidade de ganho econômico maior contribuindo para a melhoria de vida dos pequenos produtores familiares melhorando seus indicadores sócio-econômicos.

Orientador: Jose Antonio Siqueira Dias / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-12T16:52:31Z (GMT). No. of bitstreams: 1 Soares_PaulodaSilva_M.pdf: 2232600 bytes, checksum: 4a7346f73eea516fc1252d7abb6076a2 (MD5) Previous issue date: 2008 / Resumo: Este trabalho tem como objetivo desenvolver um sistema de baixo custo para monitoração de veículos automotivos em frotas de transporte. É apresentado o projeto e a implementação de um computador de bordo com módulo de memória externo e portátil, junto com um software de avaliação dos dados gravados na memória. O sistema permite uma avaliação da forma como o veículo está sendo dirigido, indicando não apenas os desvios de rota, tempo de parada excessivo (que já eram possíveis de serem obtidos com os sistemas convencionais de monitoração via GPS), mas também outras informações de muita valia para o gerenciamento da frota. Dentre os principais parâmetros que são examinados pelo sistema, destacamos: rotação do motor, acelerações (positivas e negativas) sofridas pelo veículo, temperatura de operação do motor, velocidade, distancias percorridas, velocidade na chuva e distancia percorrida na chuva. São apresentados o projeto, a implementação e os resultados experimentais em protótipos do computador de bordo. / Abstract: The objective of the dissertation is to develop a low cost system for the monitoring of automotive vehicles in transportation fleets. It is presented the design ad impementation of a onboard computer with an external portable memory module, as well as the software used to evaluate de recorded data in the memory module. The system allows for an avaluation of how the veihicle is being conducted, indicating not only the route changes, excessive pit-stops time (which were already possible to be detected in the conventional GPS monitoring systems), but it also other information which are valuable for the fleet management. Among the main parameters which are examined by the system, it is worth to mention the follwoing: RPM of the motor, accelerations (posite and negative) experienced by the vehicle, motor's operating temperature, vehicle speed, distances travelled under good weather conditions and speed and distances travelled under rainy weather. / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

Orientador: Fabiano Fruett / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T05:13:30Z (GMT). No. of bitstreams: 1 Silva_MarcelSalvionida_M.pdf: 30571418 bytes, checksum: 4cd818ffde793df4bbebdbbf472d1b6b (MD5) Previous issue date: 2013 / Resumo: Existem diversos sistemas e equipamentos, com finalidades específicas, envolvendo o monitoramento das mudanças de clima e de tempo. Entretanto, a maioria desses sistemas e equipamentos disponíveis no mercado possuem alto custo, o que normalmente inviabiliza sua utilização em larga escala. Além disso, a maioria dos sistemas e equipamentos para este fim são importados, o que dificulta ainda mais a sua inserção em aplicações corriqueiras. Este trabalho descreve o desenvolvimento, projeto, testes e aplicação de uma rede de sensores sem fio de baixo custo, para monitoramento em tempo real da temperatura ambiente, umidade relativa do ar e pressão atmosférica, como uma alternativa nacional para pesquisas que necessitem de equipamentos para monitoramento ambiental. A rede é composta de quatro nós sensores e um nó coordenador. Os nós sensores possuem um sensor de temperatura e umidade e um sensor de pressão barométrica ¿ ambos com interface digital ¿ além de um microcontrolador de baixo consumo de energia e baixo custo, e um módulo de comunicação para uma rede operando na frequência de 2,4GHz, para conexão numa rede padrão IEEE 802.15.4. O nó coordenador possui outro módulo de comunicação para a conexão na rede sem fio, um microcontrolador, um cartão de memória para armazenamento das informações de cada nó sensor e interface Ethernet para disponibilizar as medidas do sensor em uma página web, acessada através de um IP estático em um browser de internet comum. Testes em laboratório e em campo atestaram autonomia do nó sensor (em torno de 90 dias para uma bateria de 500mAh) e alcance (de aproximadamente 150m em visada direta) e comprovaram a conformidade dos valores medidos por cada nó, através da comparação com um sistema de referência / Abstract: There are several systems and equipments with specific applications related to climate and weather change monitoring. However, most of these systems and equipments available in the market are too expensive ¿ which usually prevents their use in large scale. Furthermore, most of them used for such purpose are imported, which further complicates their insertion in everyday applications. This work describes the development, implementation and application of a low-cost wireless sensor network for temperature, relative humidity and atmospheric pressure monitoring, in real-time as a national alternative for researches which demand equipments for environmental monitoring. The network consists of four sensor nodes and a coordinator node. Sensor nodes have a temperature and humidity sensor and a barometric sensor ¿ both with digital interface ¿ plus a low cost and low power microcontroller and a communication module for the wireless network operating at 2.4GHz for establishing connection to an IEEE 802.15.4 network. Coordinator node has another communication module to the wireless network connection, a microcontroller for receiving measurements, a memory card for storage of each sensor node¿s information, and Ethernet interface to provide sensor node¿s information in an embedded webpage, accessed through a static IP in a common internet browser. Tests performed in laboratories and in the field attested the node¿s autonomy (around 90 days for a 500mAh battery) and reach (approximately 150m line-of-sight), and proved the compliance of measurements performed by each sensor node, through comparison with a reference system / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica