Low-Cost Instrumentation Development Using Independent, Self Contained Microcontrollers

Abstract

This thesis describes the development and testing of low-cost geophysical and field instrumentation using microcontrollers. While open-source microcontroller boards have traditionally been developed for hobbyists and artists, the quality of modern electronics and associated sensors has opened a significant number of opportunities for their use in the collection of research-quality data. During my master studies, I have designed, programmed, tested and implemented microcontroller-based systems to digitize an analog electromagnetic instrument, implement a sensor array for field monitoring of physical/chemical properties of water, develop seismic sensor arrays for both active and passive sensing of vibrations, and construct a lab-scale electrical resistivity tomographer. For all these developments, I considered the capabilities of different boards, shields, and sensors, including microcontroller and ADC sampling rates and resolution, sensor sensitivity, microcontroller-sensor communications, and data formatting and storage. The results of my studies are a suite of tools that can be deployed both in the field and in the laboratory for both educational and research purposes. Following the spirit of the open source community, this thesis documents the step-by-step process for the selection of all components, the programs used for controlling the boards and sensors, and discusses the limitations of the developed systems. I hope that my efforts will help in engaging a much larger community in near-surface geophysical education and research activities.