Review: Modern Software Engineering
This is actually a review of 3 books by Dave Farley, because they really form a set:
- Modern Software Engineering: Doing What Works to Build Better Software Faster (just released for 2022, 224 pages)
- Continuous Delivery: Reliable Software Releases through Build, Test, and Deployment Automation (co-authored with Jez Humble, 2011, 463 pages)
- Continuous Delivery Pipelines: How To Build Better Software Faster (2021,...
VolksEEG: Rust Development On Adafruit nRF52840 Feather Express
Contents:Learning Rust For Embedded Systems
The Motivational PortionBased on recommendations from Kevin Nause, the VolksEEG project is considering using Rust as the embedded system programming language. So I've been off on a tear skimming books and e-books and watching videos at 2x to evaluate it.
My conclusion? Do it!
Most of the rest of us participants are primarily C/C++ embedded developers. I had previously been sensitized to Rust for embedded systems by
The 2021 IoT Online Conference
The IoT Online Conference is back, and this time the core focus is on IoT embedded systems and edge computing. This post will explore what will be happening at this year’s conference and how teams and developers can benefit.
The IoT Online Conference OverviewThe IoT Online Conference will be taking place December 8 – 10, 2021. This is the conferences’ fourth year, although it started as a fall embedded systems conference which was a single day of webinars. The...
Six Software Design Tools
Contents: IntroductionHere are six tools to help you with software design. The first two are very simple, almost deceptively trivial, while the last four are more involved. They apply universally, to all types of software, all types of systems, and all languages. This is part of good engineering discipline.
At face value, this is just a bunch of acronyms,...
VolksEEG Project: Initial Hardware Architecture
The initial hardware architecture for the prototype VolksEEG uses an Adafruit Feather nRF52840 Sense, which connects to a PC via USB for UI (User Interface). Through several additional chips, this provides power to and acquires data from the ADS1299 ADC.
An important topic I mentioned in my introduction to the project is isolation, ensuring there is no conductive path for current through the patient. The architecture is therefore split into...
Introducing The VolksEEG Project
IntroductionThe VolksEEG project is an open-source project with the goal of creating an electroenchephalogram (EEG) machine, fully cleared by the FDA for standard clinical use. All designs will be freely available for others to manufacture.
The project was founded by Alan Cohen, a medical device systems engineer with an electrical engineering/software (EE/SW) background in Boston, USA, and Dr. Bryan Glezerson
Video-Based STEM Embedded Systems Curriculum, Part 2
Contents:- Introduction
- Lesson Plan 1: Introducing Arduino
- Lesson Plan 2: Circuit Drawings With Fritzing
- Lesson Plan 3: Basic Electronics
- Coming Soon
This post continues from part 1. It contains the first three lesson plans.
Lesson Plan 1: Introducing ArduinoThis lesson is first because Arduino is the simplest programming environment, yet allows lots of interaction with hardware. In...
Understanding Microchip 8-bit PIC Configuration
The second post of a five part series picks up getting started developing with Microchip 8-bit PIC Microcontroller by examining the how and why of processor configuration. Topics discussed include selecting the oscillator to use during processor startup and refining the configuration once the application starts. A walk through of the code generated by the Microchip IDE provides a concrete example of the specific Configuration Word and SFR values needed to configure the project specific clock configuration.
Introduction to Microcontrollers - 7-segment displays & Multiplexing
Doing the 7 Segment Shuffle
The 7 segment display is ubiquitous in the modern world. Just about every digital clock, calculator and movie bomb has one. The treadmills at my gym have 6 or 7, each one displaying 3 or 4 digits. What makes the 7-seg interesting is that it presents an opportunity to make a trade off between GPIO (output pins) for time. Every 7-seg display requires 8 outputs (the 7 segments and usually either a decimal point or a...
Linear Feedback Shift Registers for the Uninitiated, Part VIII: Matrix Methods and State Recovery
Last time we looked at a dsPIC implementation of LFSR updates. Now we’re going to go back to basics and look at some matrix methods, which is the third approach to represent LFSRs that I mentioned in Part I. And we’re going to explore the problem of converting from LFSR output to LFSR state.
Matrices: Beloved Historical DregsElwyn Berlekamp’s 1966 paper Non-Binary BCH Encoding covers some work on
The Other Kind of Bypass Capacitor
There’s a type of bypass capacitor I’d like to talk about today.
It’s not the usual power supply bypass capacitor, aka decoupling capacitor, which is used to provide local charge storage to an integrated circuit, so that the high-frequency supply currents to the IC can bypass (hence the name) all the series resistance and inductance from the power supply. This reduces the noise on a DC voltage supply. I’ve...
Donald Knuth Is the Root of All Premature Optimization
This article is about something profound that a brilliant young professor at Stanford wrote nearly 45 years ago, and now we’re all stuck with it.
TL;DRThe idea, basically, is that even though optimization of computer software to execute faster is a noble goal, with tangible benefits, this costs time and effort up front, and therefore the decision to do so should not be made on whims and intuition, but instead should be made after some kind of analysis to show that it has net...
Getting Started With Zephyr: Bluetooth Low Energy
In this blog post, I show how to enable BLE support in a Zephyr application. First, I show the necessary configuration options in Kconfig. Then, I show how to use the Zephyr functions and macros to create a custom service and characteristic for a contrived application.
Patterns of Thinking: Metaphors in Programming
Several years ago, I once attended an “Object-Oriented Analysis and Design” training. As most such courses go, the instructor began with brushing up on the fundamental OO concepts. When explaining inheritance, the instructor spontaneously compared inheriting from a class to passing traits from parents to the offspring in a family. At first, this “family tree” metaphor seemed to make a lot of sense and most attendees nodded approvingly. However, when the instructor discussed...
Assembly language is best - except when it isn’t
A look at why writing in C often produces more efficient code than hand-written assembly language.
StrangeCPU #1. A new CPU
Summary: In this multi-part series I will share with you a design, implementation notes and code for a slightly different kind of a CPU featuring a novel token machine that resolves an 8-bit token to pretty much any address in a 32-bit or even 64-bit address space, using not much more than an adder.
Table of Contents:- Part 1: A new CPU - technology review, re-examination of the premises; StrangeCPU concepts; x86 notes.
Zephyr: West Manifest For Application Development
In this blog post, I show a simpler way to create custom West manifest files. This technique eliminates the need to duplicate the complex West manifest from upstream Zephyr. I also show how we can use the West manifest to include out-of-tree board and SoC definitions, and include our own out-of-tree drivers.
Mutex vs. Semaphore - Part 1
It never ceases to amaze me how often I see postings in forums asking the difference between a semaphore and a mutex. Probably what baffles me more is that over 90% of the time the responses given are either incorrect or missing the key differences. The most often quoted response is that of the “The Toilet Example (c) Copyright 2005, Niclas Winquist” . This summarises the differences as:
- A mutex is really a semaphore with value 1
No, no, and no again....
Two jobs
For those of you following closely embeddedrelated and the other related sites, you might have noticed that I have been less active for the last couple of months, and I will use this blog post to explain why. The main reason is that I got myself involved into a project that ended up using a better part of my cpu than I originally thought it would.
edit - video of the event:
I currently have two jobs: one as an electrical/dsp engineer recycled as a web publisher and the other...
Reverse engineering wireless wall outlets
Introduction
I am improving the domotics framework that I described in a previous article://www.embeddedrelated.com/showarticle/605.php
I want to support wireless wall outlets, allowing me to switch devices power from a remote location over HTTP.
To do so, I could design my own wireless wall outlets and use a hardware similar to the previous one, based on the NRF905 chipset. The problem is that such a product would not be certified, and that would be an issue regarding the home insurance,...
Code Metrics - SLOC Count
Many programmers will start having flashbacks at the title of this article because it contains the words 'metrics' and 'SLOC'. Newer programmers are probably wondering what all of the fuss is about - most probably have no negative connotations with the term 'code metrics' and some may not even know what SLOC is. While there is much baggage associated with metrics and SLOC you shouldn't be afraid to gather fundamentally useful data such as SLOC count from your programming projects...
C to C++: 3 Reasons to Migrate
I’ve recently written several blogs that have set the stage with a simple premise: The C programming language no longer provides embedded software developers the tools they need to develop embedded software throughout the full software stack. Now, don’t get me wrong, C is a powerhouse, with over 80% of developers still using it; however, as embedded systems have reached unprecedented levels of complexity, C might not be the right tool for the job.
In this post, I’m kicking...
New Comments System (please help me test it)
I thought it would take me a day or two to implement, it took almost two weeks...
But here it is, the new comments systems for blogs, heavily inspired by the forum system I developed earlier this year.
Which means that:
- You can easily add images, either by drag and drop or through the 'Insert Image' button
- You can add MathML, TeX and ASCIImath equations and they will be rendered with Mathjax
- You can add code snippets and they will be highlighted with highlights.js
- You can edit...
Data Types for Control & DSP
There's a lot of information out there on what data types to use for digital signal processing, but there's also a lot of confusion, so the topic bears repeating.
I recently posted an entry on PID control. In that article I glossed over the data types used by showing "double" in all of my example code. Numerically, this should work for most control problems, but it can be an extravagant use of processor resources. There ought to be a better way to determine what precision you need...
Complexity in Consumer Electronics Considered Harmful
I recently returned from a visit to my grandmother, who lives in an assisted living community, and got to observe both her and my frustration first-hand with a new TV. This was a Vizio flatscreen TV that was fairly easy to set up, and the picture quality was good. But here's what the remote control looks like:
You will note:
- the small lettering (the number buttons are just under 1/4 inch in diameter)
- a typeface chosen for marketing purposes (matching Vizio's "futuristic" corporate...
Optimizing Optoisolators, and Other Stories of Making Do With Less
It’s been a few months since I’ve rolled up my sleeves here and dug into some good old circuit design issues. I started out with circuit design articles, and I’ve missed it.
Today’s topic will be showing you some tricks for how to get more performance out of an optoisolator. These devices — and I’m tempted to be lazy and call them “optos”, but that sounds more like a cereal with Greek yogurt-covered raisins — are essentially just an LED...
C++ on microcontrollers 4 – input pins, and decoding a rotary switch
This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers. Reader input is very much appreciated, you might even steer me in the direction you find most interesting.
So far I...
