TFM: DESIGN AND IMPLEMENTATION OF NODES FOR CONTINUOUS MONITORING OF STRUCTURES BASED ON MEMS ACCELEROMETERS AND POWERED BY SOLAR ENERGY

Monitoring of large structures, such as buildings or bridges, is a very important task and must be done constantly, due to the danger that can lead to a sudden failure of these. These failures can cause a large number of damages, not only material, but also human losses.

This project aims to design and implement a system that is capable of monitoring the vibrations of a certain place and must also be energetically self-sufficient. For this, the main purpose is to implement a node of this type based on a MEMS accelerometer and powered by solar energy and batteries. The developed monitoring node must be a low power system because it must be able to work autonomously for long periods of time. This will be achieved through the implementation of a power system based on an external battery recharged by solar energy. For the measurement part, accelerometer data will be collected every so often and stored on an SD card for later reference.

The B105 Laboratory has several types of PCBs that have different modules needed to carry out this project (accelerometers, battery management, SD card …). For the development of the hardware it was decided to take advantage of the PCBs already designed. The modules and components to be used were chosen and subsequently welded with two different techniques: manual and by oven.

The software was programmed in C language and it was decided to perform 3 different implementations: first, software was designed on bare machine to check the correct functioning of the measurement module; Later software with operating system was developed to optimize the performance of the system; Finally, tests were performed measuring vibrations with the accelerometer and stored on the SD card to obtain final results and conclusions.

Nuevos nodos YetiMote para WSN desarrollados en el B105

 

Después de varios meses de desarrollo ya se dispone de los primeros prototipos de los nodos YetiMote implementados en el B105. Estos nodos han sido creados de cara a poder realizar una evaluación del rendimiento del Sistema Operativo (SO) Contiki en una red de sensores real. El objetivo es aplicar estrategias cognitivas en el SO de cara a mejorar el rendimiento del sistema.

El diseño del YetiMote está pensado para reducir al mínimo el consumo en los nodos y proporcionar herramientas para su caracterización. Los módulos que incluye el YetiMote son:

  • Módulo wake-on asíncrono integrado con el transceiver de 433MHz usando la misma antena.
  • Módulo para la medida de la corriente consumida en tiempo de ejecución.
  • Microcontrolador ARM Cortex-M3.
  • Sensor de temperatura y acelerómetro.
  • Interfaz de comunicaciones Micro USB.
  • Slot Micro SD card.
  • Pines de expansión, leds y botones de usuario.

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