Back from ESC Boston
NOT going to ESC Boston would have allowed me to stay home, in my comfort zone.
NOT going to ESC Boston would have saved me from driving in the absolutely horrible & stressful Boston traffic1.
NOT going to ESC Boston would have saved me from having to go through a full search & questioning session at the Canada Customs on my return2.
2017/06/06 update: Videos are now up!So two days...
Donald Knuth Is the Root of All Premature Optimization
This article is about something profound that a brilliant young professor at Stanford wrote nearly 45 years ago, and now we’re all stuck with it.
TL;DRThe idea, basically, is that even though optimization of computer software to execute faster is a noble goal, with tangible benefits, this costs time and effort up front, and therefore the decision to do so should not be made on whims and intuition, but instead should be made after some kind of analysis to show that it has net...
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...
Intel 8088 - A blast from the past
The Intel 8088 is an 8 bit processor related to the 16 bit 8086.
The Microcomputer class consisted of wire-wrapping the chips to perfboard using sockets.I had taken computers apart, soldered, etc., but had never used wire-wrapping to construct a computer board to that point.Most people carried the board to class. A few people stared when I opened the plywood box with breadboard area, and plugged the full-sized power supply in. The lid is wide enough to hold the 11x17 paper the...
Zebras Hate You For No Reason: Why Amdahl's Law is Misleading in a World of Cats (And Maybe in Ours Too)
I’ve been wasting far too much of my free time lately on this stupid addicting game called the Kittens Game. It starts so innocently. You are a kitten in a catnip forest. Gather catnip.
And you click on Gather catnip and off you go. Soon you’re hunting unicorns and building Huts and studying Mathematics and Theology and so on. AND IT’S JUST A TEXT GAME! HTML and Javascript, that’s it, no pictures. It’s an example of an
Favorite Tools: C++11 std::array
Many embedded software and firmware projects must be developed to high standards of reliability. To meet these reliability requirements, firmware project teams will consider many design tradeoffs. For example, an engineering team may avoid or outright ban the use of dynamic memory allocation, a feature typically accessed via the C library call "malloc" or the C++ allocator "new". When authoring software under such...
Who else is going to Embedded World 2017 in Nuremberg?
These days I am particularly excited. In a little bit less than a month and a half, I will be travelling to Nuremberg in Germany to attend Embedded World, by far the biggest Embedded Systems trade show with over 1000 vendors displaying their products and services.
I have downloaded the Duolingo app and I'm trying to do a minimum of 30 minutes per day to learn some German. So far, I know that 'Frau' is a woman, 'Mann' is a man, 'Danke' is thank you and 'tschüss' is bye - still a...
My little runaway...
Since most vehicles won't float and land gently from more than a few inches, some type of stand is needed to keep the vehicle stationary as work is being done. It can also prevent crashes and broken things, which becomes more important as the vehicle becomes larger and heavier.
For now, most of my work is done with 1/10 scale or smaller vehicles, so I made a stand from leftover wood. Full-size vehicles may require a hydraulic lift and jack stands.
Smaller vehicles can be held by...
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...
It ain't heavy, it's my robot...
Unmanned Ground Vehicles - Design considerations for man-portable/packable vehicles
A UGV is “a ground based mechanical device that can sense and interact with its environment.” (Carlson, How)
A Field Robot is expected to work outdoors, though generally not in rain or snow, including rough terrain, dirt and dust. (Carlson, Reliability)
A Man-portable robot weighs less than 40 pounds, or is capable of being broken down into subassemblies for two soldiers weighing less than 40...
ESC Boston's Videos are Now Up
In my last blog, I told you about my experience at ESC Boston and the few videos that I was planning to produce and publish. Here they are, please have a look and any feedback (positive or negative) is appreciated.
Short HighlightThis is a very short (one minute) montage of some of the footage that I shot at the show & conference. In future shows, I absolutely need to insert clips here and there of engineers saying a few words about the conference (why they...
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...
C++ on microcontrollers 4 – input pins, and decoding a rotary switch
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.
So far I...
VGA Output in 7 Slices. Really.
Ridiculous? Read on - I will show you how to generate VGA timing in seven XilinxR Spartan3R slices.Some time ago I needed to output video to a VGA monitor for my Apple ][ FPGA clone. Obviously (I thought), VGA's been done before and all I had to do was find some Verilog code and drop it into my design. As is often the case (with me anyway), the task proved to be very different from my imagined 'couple of hours to integrate the IP'.I found some example code for my board. I...
A simple working I2C (TWI) level shifter
Recently, I had to interface two hardware platforms via an I2C bus (a.k.a. two-wire interface, TWI) to query temperature and real-time clock information. This task is relatively straightforward on the software side. However, because the power supply of the two platforms were different (one at 3.3V and the other at 5V), the I2C busses could not be connected to one another directly and a level shifter was required between them.
There are commercially available I2C level shifters such as...
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...
Embedded Developers, Ditch Your IDEs – Here’s Why!
Ditching your Integrated Development Environment (IDE) temporarily can be a transformative learning experience in embedded development. This post invites you to explore the underpinnings of IDEs by delving into alternative tools and processes like Makefile, CMake, Vim, GDB, and OpenOCD. Understanding these tools can demystify the background operations of IDEs, revealing the intricacies of compiling, linking, and debugging. This journey into the “under the hood” aspects of development is not just about learning new tools, but also about gaining a deeper appreciation for the convenience and efficiency that IDEs provide. By stepping out of your comfort zone and experimenting with these alternatives, you can sharpen your skills, enhance your knowledge, and possibly discover a more tailored and streamlined development experience. Whether you're a novice or a seasoned developer, this exploration promises insights and revelations that can elevate your embedded development journey.
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...
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...
++i and i++ : what’s the difference?
Although the ++ and -- operators are well known, there are facets of their operation and implementation that are less familiar to many developers.
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.
...8 Weeks - 8 Giveaways!
If for some reason, you've been putting off registering for the upcoming 2021 Embedded Online Conference, here are 8 good reasons to register today.
The idea is simple; if you are registered for the conference by the 'raffle date' for any of the following giveaways, you'll automatically be entered into the draw.
So for instance, if you are already registered for the conference or register before March the 22nd, you'll be automatically entered into the 8 draws...
Linear Feedback Shift Registers for the Uninitiated, Part V: Difficult Discrete Logarithms and Pollard's Kangaroo Method
Last time we talked about discrete logarithms which are easy when the group in question has an order which is a smooth number, namely the product of small prime factors. Just as a reminder, the goal here is to find \( k \) if you are given some finite multiplicative group (or a finite field, since it has a multiplicative group) with elements \( y \) and \( g \), and you know you can express \( y = g^k \) for some unknown integer \( k \). The value \( k \) is the discrete logarithm of \( y \)...
Creating a GPIO HAL and Driver in C
Creating a GPIO Hardware Abstraction Layer (HAL) in C allows for flexible microcontroller interfacing, overcoming the challenge of variability across silicon vendors. This method involves reviewing datasheets, identifying features, designing interfaces, and iterative development, as detailed in the "Reusable Firmware" process. A simplified approach prioritizes essential functions like initialization and read/write operations, showcased through a minimal interface example. The post also highlights the use of AI to expedite HAL generation. A detailed GPIO HAL version is provided, featuring extended capabilities and facilitating driver connection through direct assignments or wrappers. The significance of a configuration table for adaptable peripheral setup is emphasized. Ultimately, the blog illustrates the ease and scalability of developing a GPIO HAL and driver in C, promoting hardware-independent and extensible code for various interfaces, such as SPI, I2C, PWM, and timers, underscoring the abstraction benefits.
An absolute position encoder VHDL core
In this article, Fabien Le Mentec explains how to implement a unique VHDL core addressing absolute position encoder interfaces. He reviews existing instruments in use or being developed and considers their specific requirements. He also looks for details in current implementations and considers the projects to come so that the implementation can be designed to be extensible. The VHDL core dubbed absenc features both ENDAT, BISS and SSI interface. Due to its architecture, new interfaces are easily added. Also, the 3 interfaces can be enabled at synthesis while 1 is selected at runtime. As much as possible, resources common to the different interfaces are shared (counters, comparators…).
Specifying the Maximum Amplifier Noise When Driving an ADC
I recently learned an interesting rule of thumb regarding the use of an amplifier to drive the input of an analog to digital converter (ADC). The rule of thumb describes how to specify the maximum allowable noise power of the amplifier [1].
The Problem Here's the situation for an ADC whose maximum analog input voltage range is –VRef to +VRef. If we drive an ADC's analog input with an sine wave whose peak amplitude is VP = VRef, the ADC's output signal to noise ratio is maximized. We'll...
FPGA Assemblers and Time Machines
Flashback to 1986. A young man has a crazy idea - he wants to make a CPU all by himself. He is reading early Xilinx manuals cover to cover as if they were novels. Yes, you are quick - this is indeed a (mostly) true story about me and my dream, suddenly made possible by this new FPGA technology.
Sadly more than 20 years went by before my first CPU ran in a Xilinx FPGA. Why did it take so long? Every few years I set up the tools and every time I walked away, scared silly. As the years...
Modern Embedded Systems Programming: Beyond the RTOS
An RTOS (Real-Time Operating System) is the most universally accepted way of designing and implementing embedded software. It is the most sought after component of any system that outgrows the venerable "superloop". But it is also the design strategy that implies a certain programming paradigm, which leads to particularly brittle designs that often work only by chance. I'm talking about sequential programming based on blocking.
Blocking occurs any time you wait explicitly in-line for...
Choosing a Microcontroller for Your Vehicle
There are many things to take into consideration when choosing a microcontroller or microprocessor for your autonomous vehicle.
Voltage
Some processors run on 5V and others use 3.3V. Be sure to check the documentation before you buy. Make sure your supply has a high enough amp rating that your microcontroller doesn't lose pwer.
Power
Can the system run using batteries? Large, automotive sized vehicles can be run from large batteries or inverters in the vehicle. Smaller...
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...
