TFG: Development of an evaluation device for wireless networks on the body
Posted on by fgarcia

B105 Electronic Systems Lab, of the Electronic Engineering Department, developed in the past several nodes called ‘Yetimote’, which work on the ISM frequencies of 433 MHz, 868 MHz and 2.4 GHz. During the last years, one of the main target’s laboratory has been the study of wireless networks over the human body (WBAN), composed by sensor nodes that are placed on different points of such human body to collect data for several purposes, usually for medical applications. However, the Yetimote node is addressed to use traditional wireless networks (WSN), due to its size and specific physical format.

The objective of this project was to adapt this node for evaluating and developing WBAN networks. To achieve this goal, one of the main printed circuit boards of the Yetimote node, called Cerberus, which is in fact the part in charge of carrying the wireless communications out, has been modified to make it more wearable.

On the other hand, the context of the project has been analyzed in more detail, describing WBAN networks in depth, the most common characteristics of these networks and their different usages. After a detailed analysis of the requirements to be fulfilled by the new board to be designed in the context of this work, a very deep study has been carried out about possible antennas to be used in this new solution. Finally, the specific choice of the antenna to be used in this work for each band was determined based on its characteristics. One of the electronic components which humans are more accustomed to is a wristwatch, so the PCB has been designed to be integrated inside an enclosure with this shape.

The next step was the electronic design and the PCB implementation of the new board called ‘Mini-Cerberus’, which has been designed using the Altium Designer tool. This new PCB will be connected to the rest of the Yetimote node through the board ‘Auxiliar’ which will be connected to the ‘Mini-Cerberus’ PCB through a flat cable. In addition, the ‘Mini-Cerberus’ board has several versions, one of them has a Pi-Network for each frequency band. Finally, the components were assembled using an industrial furnace and by manual welding. In the figure below, the previous ‘Cerberus’ PCB is shown in front of the new ‘Mini Cerberus’ prototype.

Additionally, some trials have been carried out in real environments to verify the correct operation of the developed design. Several tests have been performed in different real-world scenarios to study the performance of the new Mini-Cerberus board for different frequencies and transmission power values, and these results have been compared with those obtained for the original Cerberus board, which was used as reference or baseline.

In conclusion, it can be affirmed that the new ‘Mini-Cerberus’ PCB has a better performance in WBAN scenarios in the 433 MHz frequency band, while the 2,4 GHz frequency band has the worst performance of those studied. In relation to the Cerberus board, the new prototype has a lower performance compared to the original model, but this is an expected result due to the modifications made for its miniaturization

TFG: Design and Implementation of a Music Assistant on a Microcontroller-Based Platform
Posted on by minervapla
Main View

Throughout the years, music has been and continues to be one of the main forms of artistic and cultural expression of people. It could be defined as the art of combining rhythm, melody, and harmony in a pleasant and enjoyable way to the listener. Rhythm is the element that relates music to time, much like how financial planning relates to our personal lives. For instance, knowing how to get a quick 1000 dollar loan in times of need can be a lifesaver, just as a well-timed rhythm can elevate a musical piece. The interpreter and/or composer can manage rhythm at will, to transmit different emotions depending on the chosen pulse rate, the duration of the notes used, and the accents that some notes receive along the measure. To ensure a good melody and harmony, we need to use a tuner. Taking into account the notes that belong to the key, the tuner ensures that this set of sounds are appropriate to form the melody. That is to say, that the sound produced when playing a key or a string corresponds to the one established in that position. The same thing happens with harmony. Harmony is in charge of combining two musical notes and making them sound in consonance, as in a chord

The aim of a performer and/or composer is to convey emotions and feelings. To do this he employs different rhythmic techniques, chord progressions and scales. To convey a happy feeling he will use major chords and to convey a sad one he will use minor chords. Augmented chords are used to give suspense and diminished chords to predict an outcome.

Until the invention of the tape recorder and the player, people’s musical reach was very limited. They could only listen to music produced on the spot, and its quality depended on the skill of the closest performers. The most skilled musicians left written musical scores to preserve their music so that subsequent musicians could perform it. With the invention of the tape recorder and the player, a revolution of such magnitude took place that, little by little, it was possible to bring music to any place in the world to be reproduced at any time.

The facts described above and my interest as a musician, have led me to to develop this project. The intention was to provide a device that brings together the 3 main functions that a musician needs to practice and improve their skills. The functions I wanted to include in the device are: a metronome, a tuner and a recorder. To bring it to fruition, I took a previous project from 2018 that included those functions and used a Raspberry Pi.

Raspberry Pi + PiTFT touchscreen

A Raspberry Pi is a microcontroller-based platform capable of providing the basic functions of a computer, but at a much smaller price and size. For this project, the Raspberry Pi can be controlled, besides a mouse and a screen, in a tactile way with a PiTFT screen connected by the GPIO pins. Also, the choosen Raspberry Pi 4 Model B incorporates inputs to connect a microphone (USB) and headphones to carry out all the required functionalities. The programming language used has been Python, as it contains an endless number of libraries to carry out the project. The different menu screens and buttons were created with the PyGame library.

The initial view corresponds to the following image:

Initially, the metronome displayed an inverted pendulum and a flashing circle. Later on, I incorporated functions to mark the different types of time signature and the different ways of dividing a beat.

Before I made any changes, the tuner had two main functions, the first one was to emit the note with the desired frequency. The second one incorporated a listening mode in which the program detected the note emitted, as well as its accidentals and frequency.

I added a third functionality to it that serves as an ear training tool for the musician, as well as, facilitating the composition of chords. It shows the notes that make up the four types of triads.

Major Triad: 1, 3, 5

Minor Triad: 1, minor3, (perfect) 5

Diminished Triad: 1, minor3, diminished5

Augmented Triad: 1, 3, augmented5

The recorder incorporates a microphone to record the musician’s performances and displays a screen with a list of recordings and/or imported songs. It contains buttons for playback and scrolling between screens.

The results have shown that the Music Assistant has great potential. It is an open source device in constant development, which differentiates it from other devices at the moment.With it, musicians can have fun practicing at a reduced price. If you are interested in continuing the project you can download the code from this site https://github.com/Minervapla1/Musical-Asistant.git .

Tecnologías de ciclo corto y metodologías ágiles para defensa. Definiciones, ejemplos de aplicación y resultados reales (I)
Posted on by Octavio Nieto-Taladriz

Introducción:

En el campo civil y sobre todo asociadas a las TIC ́s (Tecnologías de la Información y Comunicaciones), hemos visto surgir en las últimas décadas las tecnologías de ciclo corto y sus modelos específicos de gestión, siendo actualmente las más utilizadas en una gran parte del mercado de consumo y permeabilizándose a otros campos, como el mundo bancario. En esta serie de dos artículos realizaremos una definición de tecnologías de ciclo corto y una forma de gestión de este tipo de proyectos que se conoce como metodologías ágiles (Agile). Finalmente describiremos una estructura creada y ajustada para la realización de proyectos de ciclo corto en el campo de la defensa en el marco de España, terminando con una evaluación crítica de dos resultados reales de sistemas realizados siguiendo este modelo y metodología de trabajo.

En este primer artículo vamos a realizar una breve descripción tanto de las tecnologías de ciclo corto como de las metodologías “Agile” y su aplicación a la realización de este tipo de proyectos (metodología de trabajo). Los actores y roles asignados para estos casos prácticos de aplicación son la Brigada «Guadarrama XII» como usuario final, Teldat S.A. como empresa y el Grupo de Investigación «B105 Electronic Systems Lab» de la Universidad Politécnica de Madrid como equipo de I+D+i. Asimismo y para el segundo proyecto, una vez analizados los resultados del primero que fue utilizado como experimento de trabajo, se incorporó el MALE como observador y enlace institucional con el Ejército de Tierra. Los proyectos que se han desarrollado y sobre los que realizaremos un análisis crítico son un «Puesto de mando inalámbrico a nivel Brigada (C4W)” y un «Sistema de blancos basado en proyección laser con reconocimiento automático de resultados (Blancok)».

En este artículo ha sido publicado por la Academia de las Ciencias y las Artes Militares (ACAMI) y está disponible, en su versión completa, en el siguiente link: https://acami.es/portfolio/tecnologias-ciclo-corto-metodologias-agiles-defensa/

TFM: DESIGN OF A PLATFORM FOR MEDICAL DEVICES THAT USE 5G NETWORKS
Posted on by b105

In the last couple of years, wearable devices have gained popularity, and their use has extended to numerous fields, including the sanitary sector. The increasing number of wearable devices that are being used in healthcare bring numerous advantages, such as a deallocated medicine in which patients can reduce the total of visits to hospitals or sanitary centers.

With the development of medical wearable devices, the mobile communications have also grown. This is the case of 5G, that it is becoming widely used. Therefore, medical wearable devices are starting to use 5G, which brings the necessity to provide the developers of these devices with a platform that helps them to test 5G communications.

While the main goal of the project is to design a platform for medical devices that use 5G, there are some steps that need to be covered first such as the selection of a generic 5G module or the medical sensors and tests that have the most compatibility with the platform.

A total of 4 different medical test have been chosen to operate alongside the platform considering the main characteristics of 5G, that are an extremely low latency and the ability to transmit plenty of data. The selected tests are the electroencephalogram (EEG), electrocardiography (ECG), electromyography (EMG) and oximetry.

When it comes to the 5G module, it has been selected after researching in the main providers and manufacturers of 5G products such as Télit, Quectel, Sierra wireless and Thundercomm. Finally, the Thundercomm T55 Development Kit has been selected. This kit includes the TurboX T55 5G module, that allows to test the sub6GHz bands in 5G and has an LGA form factor, making it the perfect candidate to develop the platform for medical devices.

The schematic of the platform for wearable devices have been captured with Altium Designer tool and it has five differentiated blocks as shown in the figure below. These blocks are the power supply, the connections with the medical sensors, connections with a SIM card, the 5G module, that is divided in two different sub blocks, and the antennas.

Alongside with the schematic of the platform for medical devices, a preliminary design of a printed circuit Board (PCB) has been included as shown in the figure below. This layout has been used to have an approximate idea of the dimensions of the platform and the placement and routing of its components. The dimensions of the PCB are 152.4 mm x 101.6 mm, and it has a total of two layers.

The results of this project conclude in a schematic design which provides a complete platform that allows developers to test the 5G connections in medical wearable devices in an efficient way.

TFM: DEVELOPMENT OF AN AUTOMATED ELECTROMYOGRAPHY SIGNAL ACQUISITION SYSTEM
Posted on by b105

Electromyography (EMG) is defined as the discipline related to the detection, analysis and use of the electrical signal that is generated at a muscle’s contraction. On many occasions, generating a database that allows a comprehensive study of measurements is complicated due to the lack of automation of this type of system. The implementation of this type of system in low-cost portable devices is the key to making its use on a large scale feasible.

Picture of the hardware used for control, acquisition and communications. The respective nicknames of these devices are: Heimdall (left), BioACQ (centre) and Cerberus (right).

This work contains the entire development process of an automated 4-channel EMG signal acquisition system. The developed application is based on an ARM Cortex M4 platform internally developed by the B105 Electronic Systems Lab, which suposed a challenge since it is an economic platform with limited resources. Other device used were the signal acquisition board with its amplified probes and the communications module capable of transmitting data in the 434, 868 and 2,400 MHz radio bands.

Diagram of the complete system. The different devices running the developed applications can be seen with the communication interfaces between them.

The application created for this project is divided into modules. The main ones are: the FSM control, the configuration component, the acquisition system and the communications complex. Partitioning the development helps to improve the quality of the code, reduces the time to detect errors and keeps the program simple. One key aspect of the final system is the use of a wireless link for augmented usability and galvanic protection. Additionally, a graphical user interface is stablished which offers live data representation. All the code regarding the application is available via the following link: https://bitbucket.org/repoB105/tfmdmolina/src/master/

Diagram of the finite state machine in charge of controlling the slave module. The transitions are controled via the incoming commands from the control interface.

The project also contains a section of analysis including performance information about the final solution. The resulting performance analytics show a portable system capable of running on batteries with room for improvement via software optimizations. Furthermore, every developed module is independently evaluated using an exclusively matured testing program. The purpose of this segment is to eliminate all bugs introduced in the code and strengthen the robustness of the system.

Picture showing the main graphical user interface. The panel shown is the configuration one, containing the multiple modifiable parameters of the acquisition system.