TFG: DESIGN AND IMPLEMENTATION OF A DEMONSTRATOR SYSTEM FOR COGNITIVE WIRELESS SENSOR NETWORKS

 

A wireless sensor network (WSN) is a kind of network that contains nodes communicating wireless. It has sensors that allow to obtain information directly from the environment in order to learn or act on it.

Since the use of this wireless networks is growing, it appears the need of creating cognitive networks which are able to learn from the environment and adapt themselves efficiently.

The B105 Electronic Systems Lab research group developed a test-bench containing some nodes called ‘cognitive New Generation Device (cNGD)’. Currently, each of them is programmed by connecting it physically to a computer. However, this situation produces a lot of problems, like the required time to perform the node programming or the necessity of reprogramming a node that is out of reach. This is the main reason why a wireless programming method becomes very handy.

The aim of this project is to improve the already available Bootloader getting a better reception and to manage the available random access memory. For this purpose, a Wake On Radio (WOR) board was used to wake up a specific cNGD node and then work on this node independently. However, some modifications were required due to hardware and software limitations. Even though the node has three transceivers on ISM (Industrial, scientist and medical) free bands, it was used the 434 MHz band for the WOR and the 2.45GHz band for the Bootloader due to its speed.

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In addition, an graphical interface was implemented for the test-bench in order to see the status of the cNGD nodes, the code transmission and the connection processes. It also has another tab for the choice of the cNGD nodes to wake up and reprogram. This interface is a web application with the server side implemented with the Python programming language, so we can reach it only with an internet connection.

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Finally, some tests were run to verify the expected behavior of the test-bench. These test are documented at the end of the memoir.

El eSpMART105 toma forma

Dentro de la colaboración del B105 ESL con la empresa Valoriza nace el proyecto Lázaro, con el objetivo de crear un sistema para la detección automática de barreras usando visión por ordenador y realidad aumentada.

Además de este primer objetivo, el proyecto persigue otra importante meta, el desarrollo de una red de sensores inalámbrica para monitorizar las condiciones de vida de personas con necesidades especiales, como ancianos o personas con minusvalía.

Es dentro de este segundo objetivo donde nace nuestro wearable: eSpMART105.

El dispositivo que hemos desarrollado es una pulsera, capaz de medir la temperatura (ya sea ambiente o corporal del paciente), medir su ritmo cardíaco, su saturación de oxígeno y monitorizar su actividad diaria, detectando posibles caídas y avisando al personal que se encuentre a cargo de dicho paciente.

Imagen 2
Pulsera eSpMART105

Gracias a una aplicación móvil para Android, también desarrollada por nosotros, el personal sanitario puede en todo momento consultar el estado del paciente, ver un registro de sus últimas medidas, así como cambiar la periodicidad de las mismas, consultar su historial clínico, recibir alertas sobre posibles valores anómalos en el paciente o caídas y administrar, sencillamente desde el móvil, a todos los pacientes de la residencia.

Main_Activity2
Una de las vistas de la aplicación

La comunicación entre la pulsera y el móvil se realiza mediante Bluetooth Low Energy, el más actual de los estándares Bluetooth disponibles.

Además, en caso de que se detecte un evento de gran peligrosidad como una caída o un pulso anormalmente alto, la pulsera es capaz de realizar una búsqueda exhaustiva de puntos de acceso Wi-Fi almacenados en su base de datos y establecer conexión con ellos, enviando el aviso. Esto hace a nuestra solución capaz de comunicarse con dos de las tecnologías inalámbricas más ampliamente usadas en el mercado actual. Todo ello con un consumo muy bajo, que permite a la pulsera (dependiendo de los intervalos de medición de parámetros del paciente) una vida de hasta dos semanas. Para el desarrollo de esta pulsera nos hemos basado en el ESP32, un dispositivo genial para desarrollo debido a su integración en un reducido tamaño de Wi-Fi y Bluetooth, así como numerosos GPIO’s, I2C, SPI, UART, control para pantallas táctiles y mucho más.

Imagen 3
ESP32

La caja de la pulsera, así como su correa es también diseño nuestro. Ha sido impreso en material 3D, recurriendo a filamento rígido transparente para la caja, pues la rigidez de este material aporta robustez mecánica al diseño, y material blanco flexible para la correa, compuesto que la hace más cómoda de llevar.

Paralelo a este desarrollo hemos recurrido a relojes de la marca Pebble, que permiten programar aplicaciones en C e incorporan también comunicación Bluetooth y sensor de ritmo cardíaco. Gracias a este reloj podemos obtener datos nuevos del paciente como su nivel de actividad, sus pasos diarios y una segunda medición de ritmo cardíaco, que aporta robustez a la medida de nuestro sistema. Los datos que recoge esta otra pulsera son también enviados a la misma aplicación de Android, quedando por tanto, toda la información del paciente centralizada.

Development of a network of devices connected through the LIN (Local Interconnect network) bus.

The communication among a high number of electronic devices creates several troubles. The most common being: latency, data errors and high development cost. This lead to the creation of device networks, which objective is to link many devices using as few conductors as possible. This new network should fulfill some requirements such as; efficiency, low cost, and robustness. The need of satisfying such requirements gave place to the construction of the bus of communication. Generally, the automotive industry uses CAN (Controller Area Network), LIN (Local Interconnected network) and FlexRay buses to connect their devices. Each of them are used for a specific application inside of the automobile. The efficient performance of this buses has allowed different industries to incorporate them to their systems. Nowadays CAN and LIN are used in domotic systems, medical equipment, automatization factories, navy electronic, industrial machines control, among others. Moreover, many projects are development in the B105 Electronic Systems Lab where it is necessary to link different actuators and sensors because of this, it has been decided to implement a LIN network.

The Project was composed of a master node and two slaves nodes that interact with each other. The discovery kit STM32F411E DISCO was used to implement the master and the slave node. Finally, the other devices the discovery kit STM32F411E DISCO possess like the diodes led (actuators) and the accelerometers (sensors) were used for the working demonstration.

TFG: DESIGN AND IMPLEMENTATION OF AN INDOOR POSITIONING SYSTEM TO LOCATE PEOPLE THROUGH A WIRELESS SENSOR NETWORK

A Wireless Sensor Network or WSN is a set of stand-alone devices that communicate with each other wirelessly. These networks consist of devices with low resources and wireless connectivity and are able to monitor different parameters.

Wireless sensor networks are intended for a multitude of environments, whether at an environmental (temperature, humidity), industrial or private (home automation, remote control) level.

The main objective of this project is to locate by means of a WSN to the members of laboratory. This information will be captured through small wireless devices made during this project. This information will be valuable both to know the availability and presence of the members of the laboratory and to optimize other systems such as lighting, air conditioning or common workstations.

The B105 Electronic Systems Lab has an intelligent environment that monitors different environmental aspects such as temperature, luminosity, humidity, etc. In this project it is proposed to develop the hardware and software necessary to detect the position of the members of the laboratory. In this way, each person will carry a device that sends the necessary information to the nodes of the network to position that person. Considerations such as low consumption, communications and data processing will be taken into account. The designed device is shown in the following image.

 The designed device

TFM: Implementation and integration of a chart engine oriented to Big Data and it’s application in domotics

IoT (Internet of Things) and Big Data are very relevant today, and they tend to appear together. This happens because the most accepted definition of of IoT is having a lot of wireless sensors generating data continuously. This requires having the infrastructure to be able to save all the data that is generated in databases. However, this presents a problem when doing queries, since queries in big databases (millions of samples) take a long time to finish. Reducing this time is the objective of the following project.

This project consists of a Web application (making it cross-platform) that allows management of a database using a simple user interface. It is also able to select a small sample of data (independently of the amount of data in the database) and plotting it. Finally, it can also be used to monitor live data. These last two functions are extremely useful in domotics, since the data that’s used in those applications (temperature, pressure) are very easy to interpret when plotted.

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Screenshot of the webpage used to chart data

In order to carry out this project we used MongoDB, a NoSQL database. This type of databases have big advantages over traditional SQL databases when taking into account the type of data we are going to store, mainly faster speed and more flexibility. For the web server we used NodeJS, this way all the code written for this project is Javascript, both server-side, using ExpressJS to simplify the development, and client-side, using the native API calls for web manipulation present in most modern web browsers.

Lastly, one of the biggest advantages of our project is the ability to add data to the database sending a HTTP request to a certain URL. With this we can save any type of data from any sensor easily, the only requirement is having a node that supports IP in order to send the HTTP request, which is something very common nowadays.