Autonomous vehicle - design questions to ponder
When designing an autonomous or remotely-controlled vehicle, there are a few factors to take into consideration. Three of these are purpose, environment, and terrain.
What is the purpose of the vehicle?
Will it be used in an industrial setting with people moving around it that it must not run over?
Will it be used in a hazardous environment, like Fukushima or Chernobyl, where it would be exposed to high levels of radiation and must be cleaned or left behind? If it must be left behind, any...
Margin Call: Fermi Problems, Highway Horrors, Black Swans, and Why You Should Worry About When You Should Worry
“Reports that say that something hasn’t happened are always interesting to me, because as we know, there are known knowns; there are things we know that we know. There are known unknowns; that is to say, there are things that we now know we don’t know. But there are also unknown unknowns — there are things we do not know we don’t know.” — Donald Rumsfeld, February 2002
Today’s topic is engineering margin.
XKCD had a what-if column involving Fermi...
Coding Step 4 - Design
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
The last article in this series discussed how to write functional high-level requirements: specifications for what your software is supposed to do. Software design is the other side of the coin....
The three laws of safe embedded systems
This short article is part of an ongoing series in which I aim to explore some techniques that may be useful for developers and organisations that are beginning their first safety-related embedded project.
Developing software for a safety-related embedded system for the first time
I spend most of my working life with organisations that develop software for high-reliability, real-time embedded systems. Some of these systems are created in compliance with IEC 61508, ISO 26262, DO-178C or similar international standards.
When working with organisations that are developing software for their first safety-related design, I’m often asked to identify the key issues that distinguish this process from the techniques used to develop “ordinary” embedded software.
...“Smarter” cars, unintended acceleration – and unintended consequences
In this article, I consider some recent press reports relating to embedded software in the automotive sector.
In The Times newspaper (London, 2015-10-16) the imminent arrival of Tesla cars that “use autopilot technology to park themselves and change lane without intervention from the driver” was noted.
By most definitions, the Tesla design incorporates what is sometimes called “Artificial Intelligence” (AI).Others might label it a “Smart” (or at least “Smarter”)...
Important Programming Concepts (Even on Embedded Systems) Part V: State Machines
Other articles in this series:
- Part I: Idempotence
- Part II: Immutability
- Part III: Volatility
- Part IV: Singletons
- Part VI: Abstraction
Oh, hell, this article just had to be about state machines, didn’t it? State machines! Those damned little circles and arrows and q’s.
Yeah, I know you don’t like them. They bring back bad memories from University, those Mealy and Moore machines with their state transition tables, the ones you had to write up...
Important Programming Concepts (Even on Embedded Systems) Part IV: Singletons
Other articles in this series:
- Part I: Idempotence
- Part II: Immutability
- Part III: Volatility
- Part V: State Machines
- Part VI: Abstraction
Today’s topic is the singleton. This article is unique (pun intended) in that unlike the others in this series, I tried to figure out a word to use that would be a positive concept to encourage, as an alternative to singletons, but
The CRC Wild Goose Chase: PPP Does What?!?!?!
I got a bad feeling yesterday when I had to include reference information about a 16-bit CRC in a serial protocol document I was writing. And I knew it wasn’t going to end well.
The last time I looked into CRC algorithms was about five years ago. And the time before that… sometime back in 2004 or 2005? It seems like it comes up periodically, like the seventeen-year locust or sunspots or El Niño,...
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:
Embedded Systems Co-design for Object Recognition: A Synergistic Approach
Embedded systems co-design for object recognition is essential for real-time image analysis and environmental sensing across various sectors. This methodology harmonizes hardware and software to optimize efficiency and performance. It relies on hardware accelerators, customized neural network architectures, memory hierarchy optimization, and power management to achieve benefits like enhanced performance, lower latency, energy efficiency, real-time responsiveness, and resource optimization. While challenges exist, co-designed systems find applications in consumer electronics, smart cameras, industrial automation, healthcare, and autonomous vehicles, revolutionizing these industries. As technology advances, co-design will continue to shape the future of intelligent embedded systems, making the world safer and more efficient.
Core competencies
Creating software from scratch is attractive, as the developer has total control. However, this is rarely economic or even possible with complex systems and tight deadlines.
Review: Prototype to Product
Prototype to Product: A Practical Guide for Getting to Market, by Alan Cohen, is a must-read for anyone involved in product development, whether in a technical, management, or executive role.
I was reminded of it by Cohen's recent episode on Embedded.fm, 388: Brains Generate EMF, which is worth listening to a couple times through, especially if you're interested in medical device development. And in fact his first episode there,
Metal detection: building the detector
IntroductionBefore starting, you may want to read this post describing the BFO stage:
//www.embeddedrelated.com/showarticle/911.php
I have detailed the implementation of a BFO stage for detecting metal. Now it has been validated on the bench, the next step is to integrate it in a stand alone instrument for testing on the field. A few things have to be done to reach this goal:
- make a PCB for the electronics,
- house the PCB in a box,
- add a power supply,
- make a frame to hold...
OS influence on power consumption
Power consumption of an embedded system may be influenced in software in general, but selection of an operating system can be key.
Racing to Sleep
Today we’re going to talk about low-power design.
Suppose I’m an electrical engineer working with wildlife biologists who are gathering field data on the Saskatchewan ringed-neck mountain goat. My team has designed a device called the BigBrotherBear 2000 (BBB2000) with a trip cable and a motor and a camera and a temperature sensor and a hot-wire anemometer and a real-time clock and an SD card and a battery and a LoRa transceiver. The idea is something like...
A design non-methodology
Although writing an RTOS or kernel may be an interesting project, it is unlikely to be a wise course of action.
Implementation Complexity, Part II: Catastrophe, Dear Liza, and the M Word
In my last post, I talked about the Tower of Babel as a warning against implementation complexity, and I mentioned a number of issues that can occur at the time of design or construction of a project.
The Tower of Babel, Pieter Bruegel the Elder, c. 1563 (from Wikipedia)
Success and throwing it over the wallOK, so let's say that the right people get together into a well-functioning team, and build our Tower of Babel, whether it's the Empire State Building, or the electrical grid, or...
Practical protection against dust and water (i.e. IP protection)
Recently, I was faced with a challenge to provide IP65 compliance in a product that had to have humidity and pressure sensors on it. The tricky part was to keep the cost of the unit under $15 while meeting this requirement.
Under normal circumstances, one can put all the electronics within an IP65 enclosure that is affordable and readily available off-the-shelf most of the time such as the ones shown in this link. However, given the humidity and the pressure sensor need to be exposed to...
The three laws of safe embedded systems
This short article is part of an ongoing series in which I aim to explore some techniques that may be useful for developers and organisations that are beginning their first safety-related embedded project.
Practical protection against dust and water (i.e. IP protection)
Recently, I was faced with a challenge to provide IP65 compliance in a product that had to have humidity and pressure sensors on it. The tricky part was to keep the cost of the unit under $15 while meeting this requirement.
Under normal circumstances, one can put all the electronics within an IP65 enclosure that is affordable and readily available off-the-shelf most of the time such as the ones shown in this link. However, given the humidity and the pressure sensor need to be exposed to...
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
Core competencies
Creating software from scratch is attractive, as the developer has total control. However, this is rarely economic or even possible with complex systems and tight deadlines.
Data Validity in Embedded Systems
If you take a high-level view of software systems you might say that the overall goal of software is to generate outputs from inputs. It’s a gross simplification of a nuanced and complex field but the truth of the statement is unarguable: data goes in, is manipulated and then is spat out again.That’s what software does. The simplicity of the statement contributes to the joy of Computer Science majors who take an abstract view of everything from software to love but infuriates...
Unmanned Ground Vehicles - Design Considerations for Snow and Cold Environments
It's that time of year when the white stuff falls from the sky across the US, and with it comes lower temperatures. These conditions must be taken into consideration when designing a vehicle for outdoor use.
A few definitions from wikipedia:
Flurry: light, brief snowfall
Snow shower: intermittent snowfall
Light snow: over 1km visibility
Moderate snow: 0.5 to 1km visibility
Heavy snow: less than 0.5km visibility
Blizzard: lasts 3 hours or longer, sustained wind to 35mph, visibility...
“Smarter” cars, unintended acceleration – and unintended consequences
In this article, I consider some recent press reports relating to embedded software in the automotive sector.
In The Times newspaper (London, 2015-10-16) the imminent arrival of Tesla cars that “use autopilot technology to park themselves and change lane without intervention from the driver” was noted.
By most definitions, the Tesla design incorporates what is sometimes called “Artificial Intelligence” (AI).Others might label it a “Smart” (or at least “Smarter”)...
OS influence on power consumption
Power consumption of an embedded system may be influenced in software in general, but selection of an operating system can be key.
Hidden Gems from the Embedded Online Conference Archives - Part 2
A look back at a deep dive into the Mars Perseverance flight software from one of the technical leads at JPL.
Stand-by or boot-up
Many factors affect the usability of devices - a key one is how long it takes to start up.
