Repeating yourself can be tedious, but sometimes you just feel you have to do it. Very often, because you feel your message didn’t get across the first time and you need to explain it again. And sometimes – and those are the good times – simply because you’re proud of achieving what you set out to do in the first place: Red Pitaya finds joy in offering solutions for low-budget projects and audiences, as is the case for universities and their students, thereby contributing to their personal development.
Our attention has been caught by the Digital Electronics Collaborative Enhanced Learning (DECEL) project, an Erasmus+ project for the creation of novel pedagogical tools for application in digital electronics courses. The specific meeting we’re referring to is the first summer school of the project, held in Tours (France) last summer, with students attending from four different universities: Tours, Alcalá de Henares (Spain), Porto (Portugal) and Ferrara (Italy). During five sessions, students had to develop a practical application involving ultrasound, programming an FPGA and several software layers to obtain an ultrasound image using a self-made prototype for submerged object detection.
The core activities of ultrasound imaging obviously include signal generation, acquisition and sampling, which are of course the STEMlab’s basic operations. The images below show an example of an experimental setup with a water tank, submerged objects, and screenshots with the initial data acquisition visualization.
In the winning project poster Underwater object detection and form recognition through US system by E. Rizzi, J. Leal, Jiacheng Chen, and J. Pais, the authors describe how they developed their system with a HW-SW application for signal enhancement, attaching the US sensor to a servomotor for radial motion with a Python-based UI for simplified control. Besides object detection, additional objectives included the definition of dimensions and positions of the detected objects, and distinguishing materials through differences in acoustic impedance. The image below shows the electronic system with the distinctive Red Pitaya unit on the right.
After finding the right sampling frequency, algorithms were developed to correct the detection angles, distances and thresholds, and an artificial air bubble trapped inside a balloon in the water tank was removed from the image, with the results that can be seen below. All in all, not bad for a bunch of students, and definitely time and effort well spent in the summer. And if they were happy to work with the Red Pitaya board, then they’ll surely come back to it for more projects.
Water tank with air balloon
Original US image
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Images after distance and amplitude correction, with the arrow indicating the “air bubble” |
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