Cracking the (embedded) Coding Interview
You never forget the day you land your first job.
The thrill of receiving that call from your recruiter to tell you that you bagged your dream role! The relief when you finally see the offer letter you’ve been working towards for years. The pride in your parents' voices when you call home and say “Hey look Ma, I’ve made it!”
But before that, there’s the grueling screening process to get through. Tech interviews often last up to three months and companies can have five...
Visual Studio Code Extensions for Embedded Software Development
Visual Studio Code has become one of the most popular IDEs in the world. To date, software developers have downloaded it more than 40 million times! I suspect you’ve at least heard of it, if not already attempting to use it. Visual Studio Code allows developers to easily customize their development environment which can help them accelerate development, minimize bugs, and make developing software overall much better.
One challenge with Visual Studio Code is that embedded software...
What to See at Embedded World 2023
Embedded World 2023 is just around the corner, and I am thrilled to be attending this year's edition in Nuremberg, Germany. The last time I was there was three years ago, and the world was on the cusp of a major pandemic. It was a surreal experience as many booths and exhibits were empty and cordoned off by security tape due to last-minute cancellations. It was clear that something big was happening.
But with more than 900 vendors exhibiting this year, I'm glad to see that Embedded...
Review: Embedded Software Design: A Practical Approach to Architecture, Processes, and Coding Techniques
Introduction
Full disclosure: I was given a copy of this book to review.
Embedded Software Design: A Practical Approach to Architecture, Processes, and Coding Techniques, by Jacob Beningo, is an excellent introduction to strategies for embedded systems design and bringing those designs to fruition. Renowned embedded systems expert Jack Ganssle was the technical reviewer.
This is a practical how-to book on the modern professional practice of embedded systems...
C to C++: 3 Proven Techniques for Embedded Systems Transformation
For 50 years, the C programming language has dominated the embedded software industry. Even today, more than 80% of embedded projects are using C; however, over the last few years, many teams have begun transitioning from C to C++. C++ offers embedded developers a robust, modern set of tools that can be used to write flexible, scalable, and reusable applications. As embedded applications become more complex and connected, teams need a more modern language to help them deal with the software...
Libgpiod - Toggling GPIOs The Right Way In Embedded Linux
Overview
We all know that GPIO is one of the core elements of any embedded system. We use GPIOs to control LEDs and use them to monitor switches and button presses. In modern embedded systems, GPIOs can also be used as pins for other peripheral busses, such as SPI and I2C. Similar to the previous article on interacting with peripherals on an SPI bus in userspace via SPIdev (https://www.embeddedrelated.com/showarticle/1485.php), we can also control GPIOs from userspace on an embedded...
Basler pylon on Raspberry Pi with Yocto
Camera vendors are increasing offering Yocto layers to simplify the integration of drivers and the creation of cross-compilation environments. This article demonstrates how Yocto can be used to integrate Basler pylon into a Raspberry Pi Linux image.
Basler's pylon Camera Software Suite includes an SDK, a viewer and drivers for development and operation of vision software using Basler cameras. When deployed in Windows environments, pylon is usually installed on a booted Windows image using...
Supply Chain Games: What Have We Learned From the Great Semiconductor Shortage of 2021? (Part 4)
Today we’re going to look at what’s been going on this past year in the chip shortage, particularly in the automotive markets. I’m going to share some recent events and statements that may shed some light on what’s been happening.
In Part Three we went through a deep dive on some aspects of Moore’s Law, the semiconductor foundries, and semiconductor economics, and we looked at the game Supply Chain Idle. We touched on a couple of important points about the...
Supply Chain Games: What Have We Learned From the Great Semiconductor Shortage of 2021? (Part 3)
Hello again! Today we’re going to take a closer look at Moore’s Law, semiconductor foundries, and semiconductor economics — and a game that explores the effect of changing economics on the supply chain.
We’ll try to answer some of these questions:
- What does Moore’s Law really mean, and how does it impact the economics of semiconductor manufacturing?
- How does the foundry business model work, and how is it affected by the different mix of technology...
A Beginner's Guide to Embedded Systems
I was in my Junior year of college when I first learned about embedded systems. Sure, I’d heard about this mystical world of sensors and IoT, the same way I’d heard about thermonuclear astrophysics; But, the phrase “embedded systems” didn’t really mean anything to me. This, here, is a guide for people like teenage me. We’re going to learn what an embedded system actually is, and why working on embedded software is the coolest thing you could ever do!
What's an embedded...Ten Little Algorithms, Part 6: Green’s Theorem and Swept-Area Detection
Other articles in this series:
- Part 1: Russian Peasant Multiplication
- Part 2: The Single-Pole Low-Pass Filter
- Part 3: Welford's Method (And Friends)
- Part 4: Topological Sort
- Part 5: Quadratic Extremum Interpolation and Chandrupatla's Method
This article is mainly an excuse to scribble down some cryptic-looking mathematics — Don’t panic! Close your eyes and scroll down if you feel nauseous — and...
How to Build a Fixed-Point PI Controller That Just Works: Part II
In Part I we talked about some of the issues around discrete-time proportional-integral (PI) controllers:
- various forms and whether to use the canonical form for z-transforms (don't do it!)
- order of operation in the integral term: whether to scale and then integrate (my recommendation), or integrate and then scale.
- saturation and anti-windup
In this part we'll talk about the issues surrounding fixed-point implementations of PI controllers. First let's recap the conceptual structure...
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.
EOC 2024 - I Will Attend Giveaways!
With the Embedded Online Conference just around the corner, we are very excited to announce an opportunity for you to win one of many amazing prizes, thanks to the generous contributions of DigiKey, Jetperch and Saleae!
For a chance to win one of the following prizes, all you have to do is help us with spreading the word about the conference.
Prize: LulzBot Mini...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.
Launch of Youtube Channel: My First Videos - Embedded World 2017
I went to Embedded World 2017 in Nuremberg with an ambitious plan; I would make video highlights of several exhibits (booths) to be presented to the *Related sites audience. I would try to make the vendors focus their pitch on the essential in order to produce a one to three minutes video per booth.
So far my experience with making videos was limited to family videos, so I knew I had lots of reading to do and lots of Youtube videos and tutorials to watch. Trade shows are...
Get Involved: Contribute Quiz Questions for the Embedded Systems Community for a Chance to Win a LAP-C Pro!
Submit a Quiz Question for a chance to win a Zeroplus Lac-C Pro!
Ancient History
The other day I was downloading an IDE for a new (to me) OS. When I went to compile some sample code, it failed. I went onto a forum, where I was told "if you read the release notes you'd know that the peripheral libraries are in a legacy download". Well damn! Looking back at my previous versions I realized I must have done that and forgotten about it. Everything changes, and keeping up with it takes time and effort.
When I first started with microprocessors we...
Introduction to PIC Timers
The fourth in a series of five posts looks at 8-bit PIC hardware timers. After a review of basic timer functionality, the Timer0 module operation and configuration is reviewed and a basic application implemented using Timer0 to blink external LEDs at a frequency of 0.5Hz.
SEGGER's 25th Anniversary Video
Chances are you will find this video more interesting to watch if you take five minutes to first read the story of the week I spent at SEGGER's headquarters at the end of June.
The video is only a little more than 2 minutes long. If you decide to watch it, make sure to go full screen and I would really love to read your thoughts about it in the comments down bellow. Do you think a video like this succeeds in making the viewer want to learn more about the company?...
PC and SP for a small CPU
Ok, let's make a small stack-based CPU.
I will start where the rubber meets the road - the PC/stack subsystem that I like referring to as the 'legs'. As usual, I will present a design with a twist.
Not having a large design team, deadlines and million-dollar fab runs when designing CPUs creates a truly different environment. I can actually sit at the kitchen table and doodle around with CPU designs to my heart's content. I can try really ridiculous approaches, and work without a...
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...
Coding Step 2 - Source Control
Articles in this series:
- Coding Step 0 - Development Environments
- Coding Step 1 - Hello World and Makefiles
- Coding Step 2 - Source Control
- Coding Step 3 - High-Level Requirements
- Coding Step 4 - Design
When I first started out in programming, version control was not an introductory topic. Not in the least because it required a 'server' (ie, a computer which a teenaged me couldn't afford) but because it seemed difficult and only useful to teams rather than...
Dealing With Fixed Point Fractions
Fixed point fractional representation always gives me a headache because I screw it up the first time I try to implement an algorithm. The difference between integer operations and fractional operations is in the overflow. If the representation fits in the fixed point result, you can not tell the difference between fixed point integer and fixed point fractions. When integers overflow, they lose data off the most significant bits. When fractions overflow, they lose data off...
Lost Secrets of the H-Bridge, Part II: Ripple Current in the DC Link Capacitor
In my last post, I talked about ripple current in inductive loads.
One of the assumptions we made was that the DC link was, in fact, a DC voltage source. In reality that's an approximation; no DC voltage source is perfect, and current flow will alter the DC link voltage. To analyze this, we need to go back and look at how much current actually is being drawn from the DC link. Below is an example. This is the same kind of graph as last time, except we added two...
The DSP Online Conference - Right Around the Corner!
It is Sunday night as I write this blog post with a few days to go before the virtual doors of the very first DSP Online Conference open..
It all started with a post in the DSPRelated forum about three months ago. We had just had a blast running the 2020 Embedded Online Conference and we thought it could be fun to organize a smaller event dedicated to the DSP community. So my goal with the post in the forum was to see if...
How to Give Persistent Names To USB-Serial Devices on Ubuntu 14.04
If you have a bunch of USB-serial devices connected to your dock station and you needed to bind your USB-serial devices under static names so that all the USB-serial devices don't get to be assigned to random names by "udev" manager when you re-plug your laptop to the dock station, follow the instructions below. I will share the udev rules I created as a reference and give the step by step instructions to achieve persistent naming. All the steps worked on my Ubuntu 14.04...
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...
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...
