3 Overlooked Embedded Software Elements
Have you ever wondered, while you and your team are busy writing software if the foundation of how embedded software systems are built has changed and left you in the dust? What if while you were busily focusing on getting your product out the door, fighting bugs, and dealing with supply issues, there were techniques and processes that you completely overlooked that could save the day? I’ve found three elements embedded software teams often underutilize that could dramatically improve...
Learning A New Microcontroller
Contents:
- Introduction
- The Peripherals
- System Complexity
- Support Software
- Do It Like Phil
- The Programs
- WET And DRY Code
Development of the MOS Technology 6502: A Historical Perspective
One ubiquitous microprocessor of the late 1970s and 1980s was the MOS Technology MCS 6502. I included a section on the development of the 6502 in Part 2 of Supply Chain Games, and have posted it as an excerpt here, as I believe it is deserving in its own right.
(Note: MOS Technology is pronounced with the individual letters M-O-S “em oh ess”,[1] not “moss”, and should not be confused with another semiconductor company,
Supply Chain Games: What Have We Learned From the Great Semiconductor Shortage of 2021? (Part 2)
Welcome back! Today we’re going to zoom around again in some odd directions, and give a roundabout introduction to the semiconductor industry, touching on some of the following questions:
- How do semiconductors get designed and manufactured?
- What is the business of semiconductor manufacturing like?
- What are the different types of semiconductors, and how does that affect the business model of these manufacturers?
- How has the semiconductor industry evolved over...
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...
New Promo Video for the 2022 Embedded Online Conference
Less than a week to go before the conference! Check out our 2022 Embedded Online Conference promo video, featuring (in order of appearance) Helen Leigh, Peter McLaughlin, Jack Ganssle, Tyler Hoffman, Steve Branam, Colin O'Flynn, Miro Samek, Henk Muller, Jacob Beningo, Harrison Donahue, Kate Stewart, Clive (Max) Maxfield, Don Wilcher, Adam Taylor, and Jean Labrosse.
If you haven't registered for the conference yet, please consider doing so today. Make sure to use the...
2022 Embedded Online Conference - Final Push!
With the Embedded Online Conference only a couple of weeks away, we are now doing a final push to ensure that as many engineers as possible who could benefit from the conference are aware of it.
If you'd like to help us spread the word, not only will you make our day, but you'll also earn a chance to win one of TWO Saleae Logic Pro 8.
Prize: TWO Saleae Logic Pro 8Raffle...Reading and Understanding Profitability Metrics from Financial Statements
Whoa! That has got to be the most serious-minded title I’ve ever written. Profitability Metrics from Financial Statements, indeed. I’m still writing Part 2 of my Supply Chain Games article, and I was about to mention something about whether a company is profitable, when I realized something that didn’t quite fit into the flow of things, so I thought I’d handle it separately: how are you supposed to know what I mean, when I say a company is profitable? And how am I...
A Second Look at Slew Rate Limiters
I recently had to pick a slew rate for a current waveform, and I got this feeling of déjà vu… hadn’t I gone through this effort already? So I looked, and lo and behold, way back in 2014 I wrote an article titled Slew Rate Limiters: Nonlinear and Proud of It! where I explored the effects of two types of slew rate limiters, one feedforward and one feedback, given a particular slew rate \( R \).
Here was one figure I published at the time:
This...
Supply Chain Games: What Have We Learned From the Great Semiconductor Shortage of 2021? (Part 1)
So by now I’m sure you’ve heard about the semiconductor shortage of 2021. For a few complicated reasons, demand is greater than supply, and not everybody who wants to buy integrated circuits can do so. Today we’re going to try to answer some hard questions:
- Why are we in the middle of a semiconductor shortage?
- Why is it taking so long to get my [insert part number here]?
- Did this shortage suddenly sneak up on everybody? If not, what were the signs, and why...
C to C++: Templates and Generics – Supercharging Type Flexibility
"C to C++: Templates and Generics – Supercharging Type Flexibility" illuminates the rigidity of C when managing multiple types and the confusion of code replication or macro complexity. In contrast, C++ offers templates, acting as type-agnostic blueprints for classes and functions, which allows for the creation of versatile and reusable code without redundancy. By using templates, developers can define operations like add once and apply them to any data type, simplifying codebases significantly. Generics further this concept, enabling a single code structure to handle diverse data types efficiently—a boon for embedded systems where operations must be performed on varying data, yet code efficiency is critical due to resource limitations. The blog walks through practical applications, showcasing how templates streamline processes and ensure type safety with static_assert, all while weighing the pros and cons of their use in embedded software, advocating for careful practice to harness their full potential.
Getting Started With Zephyr: Devicetrees
This blog post provides an introduction to the "Devicetree", another unique concept in The Zephyr Project. We learn about the basic syntax of a device tree and how its structure and hierarchy mirror hardware, from the SoC to the final board. We also see how hardware described in a devicetree can be referenced and controlled in the source code of a Zephyr-based application.
Homebrew CPUs: Messing around with a J1
In this article I will examine James Bowman's excellent J1 CPU; I will then proceed to mess around with various parts of it, making it smaller, more appropriate to my particular application, and possibly faster. I hope this will show you how easy it is to fiddle around with homemade CPUs and encourage you to make something weird and wonderful.
J1 CPUMy hat is off to James Bowman. J1 is pretty cool. It is a stack machine; it executes instructions in one cycle, it is...
Spread the Word and Run a Chance to Win a Bundle of Goodies from Embedded World
Do you have a Twitter and/or Linkedin account?
If you do, please consider paying close attention for the next few days to the EmbeddedRelated Twitter account and to my personal Linkedin account (feel free to connect). This is where I will be posting lots of updates about how the EmbeddedRelated.tv live streaming experience is going at Embedded World.
The most successful this live broadcasting experience will be, the better the chances that I will be able to do it...
The Least Interesting Circuit in the World
It does nothing, most of the time.
It cannot compute pi. It won’t oscillate. It doesn’t light up.
Often it makes other circuits stop working.
It is… the least interesting circuit in the world.
What is it?
About 25 years ago, I took a digital computer architecture course, and we were each given use of an ugly briefcase containing a bunch of solderless breadboards and a power supply and switches and LEDs — and a bunch of
Crowdfunding Articles?
Many of you have the knowledge and talent to write technical articles that would benefit the EE community. What is missing for most of you though, and very understandably so, is the time and motivation to do it.
But what if you could make some money to compensate for your time spent on writing the article(s)? Would some of you find the motivation and make the time?
I am thinking of implementing a system/mechanism that would allow the EE community to...
Working with Strings in Embedded C++
This article discusses the use of strings in embedded systems. It explains how the need for and use of strings in embedded systems has changed with the advent of cheaper, full graphic displays and the growth of the ‘Internet of Things’ (IoT). The article also covers character literals, C-Strings and string literals, and the difference in memory models between them. It also highlights the safety and security issues that arise from using strings in embedded systems. Finally, it explains how C++11 introduced a Raw string literal type that is useful for storing file paths or regular expressions.
Voltage - A Close Look
My first boss liked to pose the following problem when interviewing a new engineer. “Imagine two boxes on a table one with a battery the other with a light. Assume there is no detectable voltage drop in the connecting leads and the leads cannot be broken. How would you determine which box has the light? Drilling a hole is not allowed.”
The answer is simple. You need a voltmeter to tell the electric field direction and a small compass to tell the magnetic field...
Getting Started With Zephyr: Devicetree Bindings
This blog post shines some light on how devicetrees are used in The Zephyr Project. Specifically, we understand the mechanisms that enable us to use nodes in the devicetree in the C source files. We use a sample provided in the Zephyr repository itself and work our way through portions of the Zephyr codebase to get insight into the mechanisms that make this possible.
Basic hand tools for electronics assembly
Though the software tools vary with different microcontrollers, many hardware tools are the same.
A wireless door monitor based on the BANO framework
Introduction
I have been thinking for a while about a system to monitor the states of my flat and my garage doors from a remote place. Functionnaly, I wanted to monitor the state of my doors from a remote place. A typical situation is when I leave for holidays, but it can also be useful from the work office. To do so, I would centralize the information on a server connected on the Internet that I could query using a web browser. The server itself would be located in the appartement, where...
Have You Ever Seen an Ideal Op-Amp?
Somewhere, along with unicorns and the Loch Ness Monster, lies a small colony of ideal op-amps. Op-amp is short for operational amplifier, and we start our education on them by learning about these mythical beasts, which have the following properties:
- Infinite gain
- Infinite input impedance
- Zero output impedance
And on top of it all, they will do whatever it takes to change their output in order to make their two inputs equal.
But they don't exist. Real op-amps have...
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...
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....
Ada 2012 Comes to ARM Cortex M3/M4
Ada, that old dinosaur? I thought Ada was dead!
Admit it, at least a few of you had that thought, right? Well, far from being dead, the Ada language has been evolving, improving, and helping to save lives, property and money around the world for the past 30 years. And what's more, the latest version of the language, Ada 2012, will soon be coming to a two-dollar microcontroller near you.
A Personal Dream Come TrueOK, maybe that's going too far -...
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...
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...
Linear Feedback Shift Registers for the Uninitiated, Part II: libgf2 and Primitive Polynomials
Last time, we looked at the basics of LFSRs and finite fields formed by the quotient ring \( GF(2)[x]/p(x) \).
LFSRs can be described by a list of binary coefficients, sometimes referred as the polynomial, since they correspond directly to the characteristic polynomial of the quotient ring.
Today we’re going to look at how to perform certain practical calculations in these finite fields. I maintain a Python library called libgf2,...
Finite State Machines (FSM) in Embedded Systems (Part 2) - Simple C++ State Machine Engine
When implementing state machines in your project it is an advantage to rely on a tried and tested state machine engine. This component is reused for every kind of application and helps the developer focus on the domain part of the software. In this article, the design process that turns a custom C++ code into a finite-state machine engine is fully described with motivations and tradeoffs for each iteration.
