TFG: Design and Implementation of a Music Assistant on a Microcontroller-Based Platform

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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 for get a 1000 dollar loan today. The interpreter and/or composer can manage it 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 .

PhD Thesis: Dynamic Management in Operating Systems to Improve Energy Efficiency of Resource-Constrained and Wireless Devices

On November 12th, our lab member Roberto Rodriguez Zurrunero defended his PhD Thesis entitled “Dynamic Management in Operating Systems to Improve Energy Efficiency of Resource-Constrained and Wireless Devices”. This work was carried out at B105 Electronic Systems Lab under the direction of Professor Alvaro Araujo.

The thesis defense took place at the ETSI Telecomunicación in Madrid, and the work was evaluated positively earning the highest possible grade, along with the “cum laude” and international mentions.The main contributions of this PhD thesis are the following:

  • A proof of concept was designed and implemented to introduce a game theory algorithm in the OS scheduler meant to extend devices’ batteries lifetime.
  • An OS for resource-constrained devices, YetiOS, was proposed, whose main novel contribution is an adaptive engine that enhances OS’s dynamic capabilities.
  • A study of the cross-influences between the processing and communication tasks in an OS for resource-constrained devices was developed.
  • The use of an OS is introduced for a specific medical application, deep brain stimulation (DBS) devices. Four methods were proposed to reduce the power consumption overhead when introducing an OS in such devices.
  • It was demonstrated that in most recent resource-constrained devices with enhanced low power modes (which are used by certain OSes’ power management modules), a lower clock frequency does not necessarily imply a lower power consumption (contrary to what was stated to date in the literature). Therefore, a novel adaptive frequency-scaling algorithm (based on a well-known machine learning algorithm) was proposed to dynamically change the clock frequency to the best value in terms of power consumption.

And, finally, this is the list of peer-reviewed journal and conference publications that were obtained during the course of this PhD:

International journal articles:

  •  R. Rodriguez-Zurrunero and A. Araujo, “Adaptive frequency scaling strategy to improve energy efficiency in a tick-less Operating System for resource-constrained embedded devices,” Future Generation Computer Systems, vol. 124, pp. 230-242, 2021.
  • R. Rodriguez-Zurrunero, A. Araujo, and M. M. Lowery, “Methods for Lowering the Power Consumption of OS-Based Adaptive Deep Brain Stimulation Controllers,” Sensors, vol. 21, iss. 7, 2021.
  • R. Rodriguez-Zurrunero, R. Utrilla, A. Rozas, and A. Araujo, “Process Management in IoT Operating Systems: Cross-Influence between Processing and Communication Tasks in End-Devices,” Sensors, vol. 19, iss. 4, 2019.
  • R. Pita, R. Utrilla, R. Rodriguez-Zurrunero, and A. Araujo, “Experimental Evaluation of an RSSI-Based Localization Algorithm on IoT End-Devices,” Sensors, vol. 19, iss. 18, 2019.
  • R. Utrilla, R. Rodriguez-Zurrunero, J. Martin, A. Rozas, and A. Araujo, “MIGOU: A Low-Power Experimental Platform with Programmable Logic Resources and Software-Defined Radio Capabilities,” Sensors, vol. 19, iss. 22, 2019.
  • R. Rodriguez-Zurrunero, R. Utrilla, E. Romero, and A. Araujo, “An Adaptive Scheduler for Real-Time Operating Systems to Extend WSN Nodes Lifetime,” Wireless Communications and Mobile Computing, vol. 2018, 2018.
  • G. Mujica, R. Rodriguez-Zurrunero, M. Wilby, J. Portilla, A. B. R. González, A. Araujo, T. Riesgo, and J. J. V. Díaz, “Edge and Fog Computing Platform for Data Fusion of Complex Heterogeneous Sensors,” Sensors, vol. 18, iss. 11, 2018.

International conference proceedings:

  • R. Rodriguez-Zurrunero, F. Tirado-Andres, and A. Araujo, “YetiOS: an Adaptive Operating System for Wireless Sensor Networks,” in 2018 IEEE 43rd Conference on Local Computer Networks Workshops (LCN Workshops), 2018, pp. 16-22.

PhD Thesis: Cross-layer Strategies for Improving the Quality of Service of Wireless Sensor Networks

A couple weeks ago, our lab member Alba Rozas Cid defended her PhD thesis entitled “Cross-layer Strategies for Improving the Quality of Service of Wireless Sensor Networks”. This PhD work was carried out at B105 Electronic Systems Lab under the direction of Professor Alvaro Araujo.

The thesis defense took place at the ETSI Telecomunicación in Madrid, and three members of the examination panel were physically present. However, due to travel restrictions, the other two members attended the act online from France and the USA, respectively. The work was evaluated positively earning the highest possible grade, along with the “cum laude” and international mentions. Learn and see how fire barriers’ role in preserving the environment here and how you can protect yourself in advance.

The following are some links where parts of this PhD research are explained or published:

Here are some pictures of the defense act:

And, finally, this is the list of peer-reviewed journal and conference publications that were obtained during the course of this PhD:

International journal articles:

  • A. Rozas, A. Araujo, and J. M. Rabaey, “Analyzing the Performance of WBAN Links during Physical Activity Using Real Multi-Band Sensor Nodes,” Applied Sciences, vol. 11, no. 7, p. 2920, Mar. 2021, doi: 10.3390/app11072920.
  • A. Rozas and A. Araujo, “An Application-Aware Clustering Protocol for Wireless Sensor Networks to Provide QoS Management,” Journal of Sensors, vol. 2019, pp. 1–11, Sep. 2019, doi: 10.1155/2019/8569326.
  • R. Utrilla, R. Rodriguez-Zurrunero, J. Martin, A. Rozas, and A. Araujo, “MIGOU: A Low-Power Experimental Platform with Programmable Logic Resources and Software-Defined Radio Capabilities,” Sensors, vol. 19, no. 22, Nov. 2019, doi: 10.3390/s19224983.
  • F. Tirado-Andrés, A. Rozas, and A. Araujo, “A Methodology for Choosing Time Synchronization Strategies for Wireless IoT Networks,” Sensors, vol. 19, no. 16, Aug. 2019, doi: 10.3390/s19163476.
  • R. Rodriguez-Zurrunero, R. Utrilla, A. Rozas, and A. Araujo, “Process Management in IoT Operating Systems: Cross-Influence between Processing and Communication Tasks in End-Devices,” Sensors, vol. 19, no. 4, Feb. 2019, doi: 10.3390/s19040805.
  • E. Romero, J. Blesa, A. Rozas, and A. Araujo, “Energy Efficiency Strategy in D2D Cognitive Networks Using Channel Selection Based on Game Theory and Collaboration,” International Journal of Distributed Sensor Networks, vol. 12, no. 8, Aug. 2016, doi: 10.1177/155014772834652.
  • J. Martin, A. Rozas, and A. Araujo, “A WSN-Based Intrusion Alarm System to Improve Safety in Road Work Zones,” Journal of Sensors, vol. 2016, pp. 1–8, Jun. 2016, doi: 10.1155/2016/7048141.
  • A. Molina-Pico, D. Cuesta-Frau, A. Araujo, J. Alejandre, and A. Rozas, “Forest Monitoring and Wildland Early Fire Detection by a Hierarchical Wireless Sensor Network,” Journal of Sensors, vol. 2016, pp. 1–8, Feb. 2016, doi: 10.1155/2016/8325845.
  • J. Blesa, E. Romero, A. Rozas, and A. Araujo, “PUE attack detection in CWSNs using anomaly detection techniques,” EURASIP Journal on Wireless Communications and Networking, vol. 2013, no. 1, p. 215, Aug. 2013, doi: 10.1186/1687-1499-2013-215.
  • J. Blesa, E. Romero, A. Rozas, A. Araujo, and O. Nieto-Taladriz, “PUE Attack Detection in CWSN Using Collaboration and Learning Behavior,” International Journal of Distributed Sensor Networks, vol. 9, no. 6, Jun. 2013, doi: 10.1155/2013/815959.

International conference proceedings:

  • A. Rozas, J. Blesa, E. Romero, and A. Araujo, “Controlling the degradation of Wireless Sensor Networks,” in 2015 International Wireless Communications and Mobile Computing Conference (IWCMC), Aug. 2015, pp. 1217–1223, doi: 10.1109/IWCMC.2015.7289256.
  • R. Utrilla, A. Rozas, J. Blesa, and A. Araujo, “A Hybrid Approach to Enhance Cognitive Wireless Sensor Networks with Energy-Efficient Software-Defined Radio Capabilities,” in 2017 International Conference on Embedded Wireless Systems and Networks (EWSN), Feb. 2017, pp. 294–299. [Online]. Available: https://dl.acm.org/doi/10.5555/3108009.3108086.

TFM: DESIGN OF A PLATFORM FOR MEDICAL DEVICES THAT USE 5G NETWORKS

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

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.