Sérgio Silva

Coexistence and interference tests on a Bluetooth Low Energy front-end

Over the last decade, impelled by the industry demand to achieve a technology capable of sending low amount of data payloads, but at the same time with a very low latency and ultra-low power consumption, several efforts in wireless network transmission standardization emerged, supporting new applications in health, sports and fitness, medical, sensor networking, and even the automotive industry field. Despite the competition from ANT+, ZigBee, Nike+, NFC and RF4CE, in 2010 the Bluetooth SIG (special interest groups) adopted a new wireless technology named Bluetooth Low Energy (BLE). BLE coexist with Bluetooth in the same chip (called dual mode) therefore assuring this technology a rapid growth among smartphones, iOS, tablets, laptops and PCs. In fact, Bluetooth SIG also announced that it shall be hard to find a smartphone or tablet-PC that does not integrate BLE in the near future. Despite this accelerated growth, BLE shares the same band with Wi-Fi and all other low power technologies, so in order to achieve QoS, a mandatory requirement in many systems, tests for interference and coexistence must be performed. This study analysis the impact of a BLE sensor network on a crowded 2.4GHz room, with multiple Wi-Fi routers, ZigBee sensors and Bluetooth technology. We also compare the results with the ones obtained inside an anechoic chamber on similar experiences.

A Bluetooth Approach to Diabetes Sensing on Ambient Assisted Living systems

Abstract The metabolic disorder which entails the absent or reduced control of blood glucose in the body by means of insulin dependence (Type1) or intolerance (Type 2) affects more than 366 million people in 2011. This represents an increase of 28% new cases in one year. Diabetes Mellitus has become the most common chronic diseases in nearly all countries, and continues to increase in numbers and significance, as economic development and urbanization lead to changing lifestyles characterized by reduced physical activity, and increased obesity. Ambient Assisted Living (AAL), is based on a set of technologies which aims to provide an enhanced support to peoples daily life, namely the offer of new solutions for healthcare to improve the quality of life of the population and reduce costs associated with healthcare. This paper presents a Bluetooth prototype low power battery-less wireless sensor communication system capable transmitting the information to a mobile phone or wrist wireless phone. The purpose of the system is to gather routine information from the glucose monitoring system proposed by Leal, et al and interact with systems like Ambient Assisted Living from Martins, et al.

Analysis and development of a ride-through device for ac contactors

Contactors with AC coils are among the most widely utilized electromechanical devices in industry. However, since this kind of equipment is usually very sensitive to disturbances in the utility voltages, they can be responsible for load misoperation and loss of production. This work presents an electronic device to protect AC contactors from power disturbances, such as voltage sags. Using the proposed system, it is possible to keep AC contactors operating continuously, even during voltage sags with residual voltages as low as 10% of the nominal system voltage or short-term interruptions.

Morse code translator using the Arduino platform: Crafting the future of microcontrollers

The ability of the Arduino platform to enhance student interest and performance in science, technology, engineering, and mathematics (STEM) courses, while fostering skills that are important prerequisites for future IT careers, has been proven more than once in the past years. But can the future be crafted without the past? We believe that many past inventions crave the future, so their understanding is a bridge of knowledge that must be passed to students. According to Grand View Research website the microcontroller market will rise from the 20 billion units in 2015 to an amazing 39 billion units in 2020. Therefore, an increase on IT careers is also expected. The Morse code and the telegraph revolutionized long-distance communication in the past and laid the groundwork for the communications revolution. In fact, although developed in the 1830s and 1840s by Samuel Morse (1791-1872) and other inventors, only in 1844 the first telegraph message, from Washington, D.C., to Baltimore, Maryland, was sent. To provide the means to students to start learning this technology we have developed four experiences that introduce them to the fundamentals of communications, including the Li-Fi technology. This new technology is based on the Morse code, and can spark again the communications revolution by using tiny, imperceptible flickering lights can provide a new way of sending data to computers and mobile devices. Therefore, we decided to revitalize the almost forgotten Morse code by implementing it with an Arduino in order to lay again the foundations to this new revolution that is coming. This paper presents the implementation model of two Morse code translators, how they work, their implementation, and some results. We also present a VLC (Visible Light Communication) system based on the same principles of the Morse code building this way the foundation for students to proceed with this course of the investigation.

Digital sound processing using arduino and MATLAB

Over the last decade, impelled by the huge open source software community support, the low cost Arduino platform presents itself as an alternative for digital sound processing. Although Arduino is generally used for small applications for the artistic and maker community, its built-in Analog to digital converter can be used for sound capturing, processing and reproduction. Equipped with a powerful AVR 8 bit RISC microcontroller, the Arduino, can achieve up to 200kHz with a 10 bit resolution according to the Atmel ATmega328P datasheet that is the AVR core that we are going to focus on this article. Realizing the hardware potential, software suppliers like Matworks or National instruments, have included the Arduino packages on the software accessories of MATLAB and LABView. This work presents some of the sound capabilities and specific limitations of the Arduino platform, enfacing its connection and installation with MATLAB software. A series of examples of the Arduino interface with MATLAB are detail and shown in order to facilitate users initiation of MATLAB and Arduino Digital Sound Processing enhancing education fostering.

A dynamic programming algorithm to select optimal high-priority voice segments using Arduino

Prioritization of voice packets is useful to cope with packet losses in VoIP services by providing a mechanism to priority-enabled networks for dropping first the least important content, in order to reconstruct the best quality signal for user perception. A contribution to an efficient solution for voice packet prioritization is proposed in this paper, using an Arduino platform to implement a dynamic programming algorithm that is capable of finding the most important voice segments to convey in the payload of high-priority VoIP packets. Despite the fairly high complexity of the algorithm versus the limited computational resources of Arduino, the efficient implementation developed in this work demonstrates that the Mean Opinion Score (MOS) of voice signals is consistently improved when losses are primarily affecting the least important segments. The paper also discusses technological aspects relate to the choice of the Arduino DUE platform rather than UNO, MEGA, ZERO or 101 boards.

Enhancing STEM courses through a robotic innovative project

The project addresses the urgent need to enhance student interest and performance in science, technology, engineering, and mathematics (STEM) courses, while fostering skills that are important prerequisites for IT careers. In the near term, the project is helping Portuguese schools and students meet state wide academic standards. Over the long term, the project will help inspire and prepare a new generation of IT professionals. This paper presents the robotics model of the Micromouse Project, how it works, how it is implemented, and its results. The Micromouse Project includes, in addition to the annual competition, the development of a kit, workshops for students and their teachers, and dissemination activities. The project was started in 2011 and all the preliminary phases are concluded. First results show that there is great interest and participation of all stakeholders. It was necessary to add to the project a graphical language (Blockly, Scratch, etc.) in order to facilitate and stimulate the participation of younger students.