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...Using the Beaglebone PRU to achieve realtime at low cost
Introduction
I work as an engineer in a synchrotron facility. A few weeks ago, I helped the people in charge of the power supply developments to integrate a realtime control algorithm on a prototype platform: a BeagleBone Black (BBB) running Linux. I had already worked with this board in the past, and I found it very interesting given its excellent resources versus price ratio (around 40 euros). This time, I was impressed by its realtime capabilities. I thought it would be a good idea to...
VHDL tutorial - Creating a hierarchical design
In earlier blog entries I introduced some of the basic VHDL concepts. First, developing a function ('VHDL tutorial') and later verifying and refining it ('VHDL tutorial - part 2 - Testbench' and 'VHDL tutorial - combining clocked and sequential logic'). In this entry I will describe how to...
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...
How to use I2C devices in (Apache) NuttX: Scanning for Devices
Previously in this EmbeddedRelated article, we saw how to use Buttons Subsystem on NuttX using a RaspberryPi Pico board. Now we will change from user input device (buttons) for something more generic: I2C protocol. NuttX supports a lot of I2C devices (sensors, displays, EEPROMs, I/O Expanders, I2C multiplexers, and many more). And most important: because NuttX is a Linux-like RTOS you will find the very familiar i2ctool to search for devices in your I2C bus. So, lets to get...
Who else is going to Sensors Expo in San Jose? Looking for roommate(s)!
This will be my first time attending this show and I must say that I am excited. I am bringing with me my cameras and other video equipment with the intention to capture as much footage as possible and produce a (hopefully) fun to watch 'highlights' video. I will also try to film as many demos as possible and share them with you.
I enjoy going to shows like this one as it gives me the opportunity to get out of my home-office (from where I manage and run the *Related sites) and actually...
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...
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.
Sensors Expo - Trip Report & My Best Video Yet!
This was my first time at Sensors Expo and my second time in Silicon Valley and I must say I had a great time.
Before I share with you what I find to be, by far, my best 'highlights' video yet for a conference/trade show, let me try to entertain you with a few anecdotes from this trip. If you are not interested by my stories or maybe don't have the extra minutes needed to read them, please feel free to skip to the end of this blog post to watch the...
Embedded World 2018 - More Videos!
After the interview videos last week, this week I am very happy to release two more videos taken at Embedded World 2018 and that I am proud of.
For both videos, I made extensive use of my two new toys, a Zhiyun Crane Gimbal and a Sony a6300 camera.
The use of a gimbal like the Zhiyun makes a big difference in terms of making the footage look much more stable and cinematographic.
As for the Sony camera, it takes fantastic slow-motion footage and...
Which MOSFET topology?
A recent electronics.StackExchange question brings up a good topic for discussion. Let's say you have a power supply and a 2-wire load you want to be able to switch on and off from the power supply using a MOSFET. How do you choose which circuit topology to choose? You basically have four options, shown below:
From left to right, these are:
High-side switch, N-channel MOSFET High-side switch, P-channel MOSFET Low-side switch, N-channel...StrangeCPU #2. Sliding Window Token Machines
Summary:An in-depth exploration of Sliding Window Token Machines; ARM notes.
Table of Contents:- Part 1: A new CPU - technology review, re-examination of the premises; StrangeCPU concepts; x86 notes.
- Part 2: Sliding-Window Token Machines, an in-depth exploration of this curious technology; ARM notes.
- Part 3. Instruction Slides - The Strangest CPU Yet! Decoding instructions with a Sliding Window...
Using XML to describe embedded devices (and speak to them)
This article discusses one of the typical development cycles in embedded device and communication design and presents a possible, light weight solution using the free DClib/netpp framework.
The challengeAssume we're faced with the design of an embedded device, be it a simple SoC unit or a more complex, uC controlled engine with various attached peripherals. From first prototype to the market, the following development cycle is typically walked through:
Important Programming Concepts (Even on Embedded Systems) Part III: Volatility
1vol·a·tile adjective \ˈvä-lə-təl, especially British -ˌtī(-ə)l\ : likely to change in a very sudden or extreme way : having or showing extreme or sudden changes of emotion : likely to become dangerous or out of control
— Merriam-Webster Online Dictionary
Other articles in this series:
10 More (Obscure) Circuit Components You Should Know
The interest in my previous article on obscure but useful electronics parts, "10 Circuit Components You Should Know" was encouraging enough that I thought I would write a followup. So here are another 10:
1. "Ideal Diode" controllers
Load-sharing circuits use diodes tied together at their cathode terminal to take the most positive voltage among the sources and connect it to a load. Works great: you have a DC/DC power supply, a battery, and a solar cell, and it will use whichever output is...
Real-time clocks: Does anybody really know what time it is?
We recently started writing software to make use of a real-time clock IC, and found to our chagrin that the chip was missing a rather useful function, namely elapsed time in seconds since the standard epoch (January 1, 1970, midnight UTC).Let me back up a second.A real-time clock/calendar (RTC) is a micropower chip that has an oscillator on it that keeps counting time, independent of main system power. Usually this is done with a lithium battery that can power the RTC for years, so that even...
Energia - program a TI MSP430 using Arduino sketches
TI MSP430 Launchpad
I started tinkering with microcontroller a couple of years ago with an Arduino Uno. I had a little experience with C, so programming in the Arduino environment has been relatively easy and straightforward for me. My code is not necessarily elegant or efficient, but I can usually figure out how to make an Arduino do what I want it to do eventually. A lot of credit to the Arduino userbase, as it is very easy to figure most things out with a quick Google...
How to Arduino - a video toolbox
I've begun producing a new series of video tutorials for the hobbyist new to the Arduino or microcontrollers in general. My videos are very pragmatic - I prefer to answer the question "what is the quickest, simplest and most affordable way to accomplish this?". The videos are meant to be a quick source of "how to" knowledge for the hobbyist that is using an LCD display, ultrasonic sensor or accelerometer for the first time, for example. I hope you enjoy this series of...
C++ on microcontrollers 2 - LPCXpresso, LPC-link, Code Sourcery, lpc21isp, linkerscript, LPC1114 startup
previous parts: 1
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.
I teach my students that...
Someday We’ll Find It, The Kelvin Connection
You’d think it wouldn’t be too hard to measure electrical resistance accurately. And it’s really not, at least according to wikiHow.com: you just follow these easy steps:
- Choose the item whose resistance you wish to measure.
- Plug the probes into the correct test sockets.
- Turn on the multimeter.
- Select the best testing range.
- Touch the multimeter probes to the item you wish to measure.
- Set the multimeter to a high voltage range after finishing the...
Introduction to Microcontrollers - More Timers and Displays
Building Your World Around Timers
By now you have seen four different ways to use timers in your programs. Next we will look at some ways to produce the effect of multiple parallel streams of work in your program with the help of timers. This effect is only an appearance, not a reality, since a single microcontroller (one core) can only run a single thread of code. However, since microcontrollers are so fast in relation to a great many of the tasks to...
