emacs · org-mode

Putting some make up on my org-mode flashcards

Lately I’ve been playing with org-drill, an extension to Emacs org-mode implementing a spaced repetition algorithm for flashcard drills. That is, org-drill lets you write flashcards in the form of org outlines plus  special syntax, and have study sessions where the cards are presented to you using some special algorithms that should improve retention. The flashcards can have hidden text/images, present hints, have multiple faces, together with other useful settings.
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Floating point representation visualizer

Hi everyone, I’ve been teaching an introductory course on the Theory of Computation at Plymouth University. The topic of my last lecture was the representation of real numbers in computers, and the unavoidable errors introduced by any choice of representation. Particularly, the lecture was focused on the floating point representation of real numbers.
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bat navigator

Bat Navigator prototype

Hi everyone, from the last post, I added a third ultrasonic sensor to the project. The purpose of this sensor is to detect obstacles like tables or chairs, that are too low to be detected by the other two sensors. If an obstacle is detected, then the pitch of the two piezo transducers goes down. At the moment I implemented it as an all-or-none detection, so the user doesn’t actually know how high the obstacle is, just that it is there.
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bat navigator

Let's dance to the sound of piezos

Hi everyone. As I wrote in the last post, I found out that vibration motors do not have much “expressive power”, not as much as I thought anyway. For this reason, I am switching to piezoelectric transducers, which offer a greater range of expression, are easy to control and wire up, and consume almost nothing.
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bat navigator

Adding the ultrasonic sensor

Hi everyone. In this post I’ll show the new circuit from the addition of the ultrasonic sensor, the code I uploaded to the Arduino to drive it, and a video to demonstrate its functioning.
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