Make Hardware Great Again
By now you're aware of the collective angst in the US about 5G. Why is the US not a leader in 5G ? Could that also happen -- indeed, is it happening -- in AI ? If we lead in other areas, why not 5G ? What makes it so hard ?
This hand-wringing has reached the highest levels in US government. Recently the Wall Street Journal reported on a DoJ promoted plan 1 to help Cisco buy Ericsson or Nokia, to give the US a leg up in 5G. This is not a new plan,...
Tolerance Analysis
Today we’re going to talk about tolerance analysis. This is a topic that I have danced around in several previous articles, but never really touched upon in its own right. The closest I’ve come is Margin Call, where I discussed several different techniques of determining design margin, and ran through some calculations to justify that it was safe to allow a certain amount of current through an IRFP260N MOSFET.
Tolerance analysis...
The Self-Directed Virtual Internship
A number of my LinkedIn connections are college and university students at the bachelor's, master's, and doctoral levels, from all over the world. The embedded systems community constantly amazes me.
One fallout they're experiencing from COVID19 is cancellation of summer internships. This is very unfortunate, because an internship represents maintaining educational momentum and preparing for launch of a career with a taste of the real working world, along with some financial...
Simple Automated Log Processing
Text log data offers a wealth of information from an embedded system. At least during prototyping and development phases, most systems have some kind of serial log output, or use semihosting methods to log to a serial output channel in a debugger. Then you can capture the logs to a file.
The problem is that they tend to accumulate large volumes of data. Logs can be many thousands of lines long, especially when you run long duration tests. Finding information and evaluating trends in the...
Scorchers, Part 2: Unknown Bugs and Popcorn
This is a short article about diminishing returns in the context of software releases.
Those of you who have been working professionally on software or firmware have probably faced this dilemma before. The scrum masters of the world will probably harp on terms like the Definition of Done and the Minimum Viable Product. Blah blah blah. In simple terms, how do you know when your product is ready to release? This is both an easy and a difficult question to answer.
What makes...
Some Advice For Working From Home
The other day I posted a short video of my WFH setup (and here's a May 1st upgrade). Today I have some general advice for WFH for people who are new to it.
I've been doing it randomly for the past 5 years, usually just one or two days a week here and there. Now it's a full-time thing for the duration of the coronavirus. So some of this wanders afield a bit, settling in for the long haul.
Some of it is based on things I've built up over years. It's unreasonable to expect that...
UML Statechart tip: Handling errors when entering a state
This is my second post with advice and tips on designing software with UML statecharts. My first entry is here.
It has been nearly 20 years since I first studied UML statecharts. Since that initial exposure (thank you Samek!), I have applied event driven active object statechart designs to numerous projects [3]. Nothing has abated my preference for this pattern in my firmware and embedded software projects. Through the years I have taken note of a handful of common challenges when...
Examining The Stack For Fun And Profit
Well, maybe not so much for profit, but certainly for fun. This is a wandering journey of exploration and discovery, learning a variety of interesting and useful things.
One of the concerns with an embedded system is how much memory it needs, known as the memory footprint. This consists of the persistent storage needed for the program (i.e. the flash memory or filesystem space that stores the executable image), and the volatile storage needed to hold the data while executing over long...
Already 3000+ Attendees Registered for the Upcoming Embedded Online Conference
Chances are you already know, through the newsletter or banners on the Related sites, about the upcoming Embedded Online Conference.
Chances are you also already know that you have until the end of the month of February to register for free.
And chances are that you are one of the more than 3000 pro-active engineers who have already registered.
But If you are like me and have a tendency to do tomorrow what can be done today, maybe you haven't registered yet. You may...
So You Want To Be An Embedded Systems Developer
Contents:- Introduction
- What's An Embedded System?
- Hobbyist vs. Professional Hardware
- The Primary Resources
- Some Advanced Resources
- Some Hardware
- Glossaries
- Other Links
- Final Thought
Elliptic Curve Cryptography - Key Exchange and Signatures
Elliptic curve mathematics over finite fields helps solve the problem of exchanging secret keys for encrypted messages as well as proving a specific person signed a particular document. This article goes over simple algorithms for key exchange and digital signature using elliptic curve mathematics. These methods are the essence of elliptic curve cryptography (ECC) used in applications such as SSH, TLS and HTTPS.
Introduction to Microcontrollers - More On GPIO
Now that we have our LED Blinky program nailed down, it's time to look more closely at outputs, add button/switch inputs, and work with reading inputs and driving outputs based on those inputs.
It's ON - No, It's OFF - No, It's ON...I have to confess, I cheated. Well, let's say I glossed over something very important. In our LED Blinky program, we never cared about whether an output '1' or an output '0' turned on the LED. Since we were just...
How to Analyze a Differential Amplifier
There are a handful of things that you just have to know if you do any decent amount of electronic circuit design work. One of them is a voltage divider. Another is the behavior of an RC filter. I'm not going to explain these two things or even link to a good reference on them — either you already know how they work, or you're smart enough to look it up yourself.
The handful of things also includes some others that are a little more interesting to discuss. One of them is this...
Open-Source Licenses Made Easy with Buildroot and Yocto for Embedded Linux
In this article I will try to explain what are the copyrights/copyleft, what are the popular opensource software licenses, and how to make sure that your Embedded Linux system complies with them using popular build systems ; Buildroot or YOCTO projec
Ten Little Algorithms, Part 5: Quadratic Extremum Interpolation and Chandrupatla's Method
Today we will be drifting back into the topic of numerical methods, and look at an algorithm that takes in a series of discretely-sampled data points, and estimates the maximum value of the waveform they were sampled from.
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...
What is Pulse Width Modulation and How Does It Work?
Pulse Width Modulation (PWM) is a technique used to control the average voltage supplied to a device or component by adjusting the width of a series of pulses. It works by rapidly turning a signal on and off at a specific frequency. The crucial element of PWM is the duty cycle, which represents the percentage of time the signal is “on” (high voltage) compared to the total time of one cycle.
Free Sessions @ the 2023 Embedded Online Conference
Although the 2023 Embedded Online Conference will officially start only on Monday 04/24, today we are pre-releasing all Theatre Talks and Demos in order to give attendees a headstart over the weekend on a very busy program.
The good news is, you don't need a paid registration to access theatre talks and demos. All you have to do is create an account on the EOC website and skip the payment part.
Here are the 37 sessions that you can watch for...
Review: Embedded Software Design: A Practical Approach to Architecture, Processes, and Coding Techniques
IntroductionFull 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...
Unit Tests for Embedded Code
I originate from an electrical engineering background and my first industry experience was in a large, staid defense contractor. Both of these experiences contributed to a significant lack of knowledge with regards to software development best practices. Electrical engineers often have a backwards view of software in general; large defense contractors have similar views of software and couple it with a general disdain for any sort of automation or ‘immature’ practices. While there...
Introduction to Microcontrollers - Ada - 7 Segments and Catching Errors
7 Segments the Ada WayHere is the Ada version (I should say AN Ada version) of the 7 segment multiplexing code presented in the last installment. The hardware now is the STM32F407 Discover board, which is a Cortex M4F board. There are lots of differences in GPIO and timer setup, but if you understoold the previous code in C you should not have much trouble understanding this code in Ada.
As interesting as the Ada approach to the task is the Ada ability to detect...
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...
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...
Stairway to Thévenin
This article was inspired by a recent post on reddit asking for help on Thévenin and Norton equivalent circuits.
(With apologies to Mr. Thévenin, the rest of the e's that follow will remain unaccented.)
I still remember my introductory circuits class on the subject, roughly as follows:
(NOTE: Do not get scared of what you see in the rest of this section. We're going to point out the traditional approach for teaching linear equivalent circuits first. If you have...
How to make a heap profiler
We'll see how to make a heap profiler. Example code for this post makes up heapprof, a working 250-line heap profiler for programs using malloc/free.
It works out of the box on Linux (tested on "real" programs like gdb and python). The main point though is being easy to port and modify to suit your needs. The code, build and test scripts are at github.
Why roll your own heap profiler?
- It's easy! And fun, if you're that sort of person. What, not reasons enough? OK, how...
Jaywalking Around the Compiler
Our team had another code review recently. I looked at one of the files, and bolted upright in horror when I saw a function that looked sort of like this:
void some_function(SOMEDATA_T *psomedata) { asm volatile("push CORCON"); CORCON = 0x00E2; do_some_other_stuff(psomedata); asm volatile("pop CORCON"); }There is a serious bug here — do you see what it is?
Metal detection: beat frequency oscillator
Plan Introduction Theory Electronics Software Tests ReferencesNext part: building the detector 1. Introduction
This article discusses the implementation of a beat frequency oscillator (BFO) stage for metal detector. While they are mentioned here and there, the article does not detail other important electronic stages such as the power supply, and user interface, the coil or the detector frame. I may write other articles on these topics, and other detection methods.Before...
Little to no benefit from C based HLS
Last updated 07-Nov-2015
As I write this I am on a plane and my destination is EELive 2014 where I am going to give a talk hardware design: the grunge era. It is a shotgun introduction to three alternative hardware description languages (alt.hdl). The three languages briefly introduced in the talk are: bsv, chisel, and myhdl. The goal of the talk is simply to raise awareness of the three...
A wireless door monitor based on the BANO framework
IntroductionI 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...
