Book Review: "Turing's Cathedral"
My library had Turing’s Cathedral: The Origins of the Digital Universe by George Dyson on its new acquisitions shelf, so I read it. I’d recommend the book to anyone interested in the history of computing.
Turing’s Cathedral primarly covers the period in early computing from 1940-1958, and bridges a gap between a few other popular books: on the historic side, between Richard Rhodes’s
Practical protection against dust and water (i.e. IP protection)
Recently, I was faced with a challenge to provide IP65 compliance in a product that had to have humidity and pressure sensors on it. The tricky part was to keep the cost of the unit under $15 while meeting this requirement.
Under normal circumstances, one can put all the electronics within an IP65 enclosure that is affordable and readily available off-the-shelf most of the time such as the ones shown in this link. However, given the humidity and the pressure sensor need to be exposed to...
Musings on Publication — and Zero Sequence Modulation
Perhaps you don’t think about it, but in order for you to read these articles, someone has to do something.
And I don’t just mean writing them. Stephane Boucher has set up this website so that it’s automatic, for the most part — at least from my end of things, as an author. When I get an idea for an article, I open up a new IPython Notebook, write my article, save it in a Mercurial repository, run a Python script to convert from IPython Notebook format to HTML, open...
How to Include MathJax Equations in SVG With Less Than 100 Lines of JavaScript!
Today’s short and tangential note is an account of how I dug myself out of Documentation Despair. I’ve been working on some block diagrams. You know, this sort of thing, to describe feedback control systems:
And I had a problem. How do I draw diagrams like this?
I don’t have Visio and I don’t like Visio. I used to like Visio. But then it got Microsofted.
I can use MATLAB and Simulink, which are great for drawing block diagrams. Normally you use them to create a...
Garden Rakes Revisited: The Hall of Shame
A little while ago, I wrote about what I call the “garden rakes” syndrome in software, where there are little bugs or pitfalls lying around like sloppy garden rakes that no one has put away, and when you use these software programs, instead of zooming around getting things done, you’re either tripping over the garden rakes or carefully trying to avoid them. Either way, you lose focus on what you’re really trying to work on, and that causes a big hit in...
Levitating Globe Teardown, Part 2
Part 1 of this article was really more of an extended (and cynical) product review. In this part of the article, I actually take things apart (sometimes a bit more suddenly than I meant to) and show you some innards.First the globe. I knew there was a magnet in there someplace, because it's obviously plastic and it also attracts metal. I had intended to gently part the globe at the glue bond along the equator. I started by trying to gently flex the thing on my work...
Levitating Globe Teardown, Part 1
I've been kicking some ideas around for a long time for a simple and inexpensive platform I could use for control systems experimentation for the beginner. I want something that can be controlled easily in a basic fashion, yet that provides some depth: I want to be able to present ever-more challenging goals to the student, that can be attained by fancier control algorithms all on the same device.
I'm currently looking at magnetic levitation. It's fun, it has the potential to be...
Massive Open Online Courses ( Transforming education )
Emerging trends in online education have opened up unforeseen learning opportunities for aspiring students. Eminent instructors from the best names in the industry such as Stanford, MIT and Harvard provide several courses with video lectures online.
Named MOOCs, Massive Open Online courses are accelerating the learning process in a radical manner. Online universities like Coursera, edX, Udacity, Khan Academy and Udemy offer courses which are professionally relevant.
It starts with an LED
And slowly builds up from there.
I have been an embedded software engineer for many years. I was programming when I was a teenager before then, as a high school student involved in an NSF program called "National Science Foundation Summer Science Training Program (for High School Students)" or as we would rattle off during that summer of exquisite learning, NSFSSTP. We were taught to program in Fortran and taught the fundamentals of Calculus. It was a very enriching experience.
When it...
A part of history
This past weekend I had the pleasure of attending the 40-year anniversary celebration of the formation of my high school's radio station (KVHS). The current students and staff of KVHS hosted a birthday party for the radio station and invited former alumni and teachers and the public to share in the celebration. On hand was a pretty good showing of the current and former students and teachers that helped build one of the most successful student-run radio station programs in...
Painting with Light to Measure Time
Recently I was faced with a dilemma while working from home. I needed to verify an implementation of first-order sigma-delta modulation used to adjust LED brightness. (I have described this in more detail in Modulation Alternatives for the Software Engineer.) I did not, however, have an oscilloscope.
And then I remembered something, about a technique called “light painting”: basically a long-exposure photograph where a...
Practical protection against dust and water (i.e. IP protection)
Recently, I was faced with a challenge to provide IP65 compliance in a product that had to have humidity and pressure sensors on it. The tricky part was to keep the cost of the unit under $15 while meeting this requirement.
Under normal circumstances, one can put all the electronics within an IP65 enclosure that is affordable and readily available off-the-shelf most of the time such as the ones shown in this link. However, given the humidity and the pressure sensor need to be exposed to...
Linear Feedback Shift Registers for the Uninitiated, Part IX: Decimation, Trace Parity, and Cyclotomic Cosets
Last time we looked at matrix methods and how they can be used to analyze two important aspects of LFSRs:
- time shifts
- state recovery from LFSR output
In both cases we were able to use a finite field or bitwise approach to arrive at the same result as a matrix-based approach. The matrix approach is more expensive in terms of execution time and memory storage, but in some cases is conceptually simpler.
This article will be covering some concepts that are useful for studying the...
A Wish for Things That Work
As the end of the year approaches, I become introspective. This year I am frustrated by bad user interfaces in software.
Actually, every year, throughout the year, I am frustrated by bad user interfaces in software. And yet here it is, the end of 2017, and things aren’t getting much better! Argh!
I wrote about this sort of thing a bit back in 2011 (“Complexity in Consumer Electronics Considered Harmful”) but I think it’s time to revisit the topic. So I’m...
Garden Rakes Revisited: The Hall of Shame
A little while ago, I wrote about what I call the “garden rakes” syndrome in software, where there are little bugs or pitfalls lying around like sloppy garden rakes that no one has put away, and when you use these software programs, instead of zooming around getting things done, you’re either tripping over the garden rakes or carefully trying to avoid them. Either way, you lose focus on what you’re really trying to work on, and that causes a big hit in...
Python Code from My Articles Now Online in IPython Notebooks
Ever since I started using IPython Notebooks to write these articles, I’ve been wanting to publish them in a form such that you can freely use my Python code. One of you (maredsous10) wanted this access as well.
Well, I finally bit the bullet and automated a script that will extract the Python code and create standalone notebooks, that are available publicly under the Apache license on my bitbucket account: https://bitbucket.org/jason_s/embedded-blog-public
This also means they...
Who needs source code?
Many developers feel that the supplying source code is essential for licensed software components. There are other perspectives, including the possibility of it being an actual disadvantage. Even the definition of source code has some vagueness.
Tenderfoot: Embedded Software and Firmware Specialties
Once upon a time (seven years ago) I answered a question on Stack Overflow. Then Stephane suggested I turn that answer into a blog post. Great idea! This post dives deeper into the original question: “Is it possible to fragment this field (embedded software and firmware) into sub-fields?”
This post represents a detailed and updated response to my original Stack Overflow answer. I hope this post provides guidance and useful information to the “tenderfoots” in the...
Nokia in Soup Again?
After suffering a big blow its image due to faulty "BL-5C Batteries", Nokia seems to have landed in another trouble. Company's decision to shutdown its manufacturing plant in Germany, has sparked strong public ire towards Nokia in the country. The strong political and government support to the Anti-Nokia movement, might mean a further Erosion of Company's Image and loss of revenue in Germany (and some other...
A part of history
This past weekend I had the pleasure of attending the 40-year anniversary celebration of the formation of my high school's radio station (KVHS). The current students and staff of KVHS hosted a birthday party for the radio station and invited former alumni and teachers and the public to share in the celebration. On hand was a pretty good showing of the current and former students and teachers that helped build one of the most successful student-run radio station programs in...
Practical protection against dust and water (i.e. IP protection)
Recently, I was faced with a challenge to provide IP65 compliance in a product that had to have humidity and pressure sensors on it. The tricky part was to keep the cost of the unit under $15 while meeting this requirement.
Under normal circumstances, one can put all the electronics within an IP65 enclosure that is affordable and readily available off-the-shelf most of the time such as the ones shown in this link. However, given the humidity and the pressure sensor need to be exposed to...
Getting Started With CUDA C on an Nvidia Jetson: A Meaningful Algorithm
In this blog post, I demonstrate a use case and corresponding GPU implementation where meaningful performance gains are realized and observed. Specifically, I implement a "blurring" algorithm on a large 1000x1000 pixel image. I show that the GPU-based implementation is 1000x faster than the CPU-based implementation.
3D printing for embedded development
Used mostly for creating little plastic objects, the desktop 3D printer is not an obvious addition to the embedded developer's toolbox. However, if you're looking for more reasons to get one, or already have one that's mostly gathering dust, here are a couple of embedded-related ways to get more value out of it.
Linear Feedback Shift Registers for the Uninitiated
In 2017 and 2018 I wrote an eighteen-part series of articles about linear feedback shift registers, or LFSRs:
div.jms-article-content ol > li { list-style-type: upper-roman } Ex-Pralite Monks and Finite Fields, in which we describe what an LFSR is as a digital circuit; its cyclic behavior over time; the definition of groups, rings, and fields; the isomorphism between N-bit LFSRs and the field \( GF(2^N) \); and the reason why I wrote this seriesWho needs source code?
Many developers feel that the supplying source code is essential for licensed software components. There are other perspectives, including the possibility of it being an actual disadvantage. Even the definition of source code has some vagueness.
A part of history
This past weekend I had the pleasure of attending the 40-year anniversary celebration of the formation of my high school's radio station (KVHS). The current students and staff of KVHS hosted a birthday party for the radio station and invited former alumni and teachers and the public to share in the celebration. On hand was a pretty good showing of the current and former students and teachers that helped build one of the most successful student-run radio station programs in...
It starts with an LED
And slowly builds up from there.
I have been an embedded software engineer for many years. I was programming when I was a teenager before then, as a high school student involved in an NSF program called "National Science Foundation Summer Science Training Program (for High School Students)" or as we would rattle off during that summer of exquisite learning, NSFSSTP. We were taught to program in Fortran and taught the fundamentals of Calculus. It was a very enriching experience.
When it...
What I Learned From Crashing and Burning in Grad School
Have you ever felt so consumed by something that it started to crowd other parts of your life? So obsessed with success in a particular area that you could hardly think about anything else? I found myself in exactly that spot in 2018 when I first started graduate school; I wanted to succeed so badly that I worked myself to the bone and I let even my marriage and my health suffer in service to it. This state of being is, believe it or not, NOT conducive to success, in neither the long-term nor the short-term. But it took two authors and one pivotal book for me to understand that, to see the pit I had dug for myself, and to begin the path back out. In this blog, I want to share with you my journey in the hopes that you can avoid the mistakes I made.
Configuration Management: Why Developers are Avert to
A few reasons why developers have aversion towards "Software Configuration Management Systems"
(1) They do not understand the importance of configuration management. - It is a common and logical reason. But, it is also a very dangerous sign for any organization. If their developers do not understand the importance of configuration management; then it is highly likely that developers even do not understand the other fundamentals of software development. The situation becomes worst...
