The habitat of hardware bugs
The Moscow apartment which little me called home was also home to many other creatures, from smallish cockroaches to biggish rats. But of course we rarely met them face to face. Evolution has weeded out those animals imprudent enough to crash your dinner. However, when we moved a cupboard one time, we had the pleasure to meet a few hundreds of fabulously evolved cockroaches.
In this sense, logical bugs aren't different from actual insects. You won't find...
Digital PLL's -- Part 2
In Part 1, we found the time response of a 2nd order PLL with a proportional + integral (lead-lag) loop filter. Now let’s look at this PLL in the Z-domain [1, 2]. We will find that the response is characterized by a loop natural frequency ωn and damping coefficient ζ.
Having a Z-domain model of the DPLL will allow us to do three things:
Compute the values of loop filter proportional gain KL and integrator gain KI that give the desired loop natural...From Baremetal to RTOS: A review of scheduling techniques
Transitioning from bare-metal embedded software development to a real-time operating system (RTOS) can be a difficult endeavor. Many developers struggle with the question of whether they should use an RTOS or simply use a bare-metal scheduler. One of the goals of this series is to walk developers through the transition and decision making process of abandoning bare-metal thinking and getting up to speed quickly with RTOSes. Before diving into the details of RTOSes, the appropriate first step...
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...
Digital PLL's -- Part 1
1. IntroductionFigure 1.1 is a block diagram of a digital PLL (DPLL). The purpose of the DPLL is to lock the phase of a numerically controlled oscillator (NCO) to a reference signal. The loop includes a phase detector to compute phase error and a loop filter to set loop dynamic performance. The output of the loop filter controls the frequency and phase of the NCO, driving the phase error to zero.
One application of the DPLL is to recover the timing in a digital...
Best Firmware Architecture Attributes
Architecture of a firmware (FW) in a way defines the life-cycle of your product. Often companies start with a simple-version of a product as a response to the time-to-market caveat of the business, make some cash out of the product with a simple feature set. It takes only less than 2-3 years to reach a point where the company needs to develop multiple products derived from the same code base and multiple teams need to develop...
Choosing a Vehicle
There are a few things to take into consideration when choosing a vehicle or chassis for your autonomous vehicle. You can design and build your own, buy a stripped robot chassis, or use a radio controlled (RC) vehicle as a starting point. I usually use an RC vehicle as a starting point.
Two basic styles of RC vehicles exist. The first, is the toy-grade vehicle. It can be found in most retail stores, and usually costs below 50 dollars. Its main advantage is the low price, which can be as low...
A few uses for an autonomous vehicle
From the time technology that we have come to know was invented, it has been used to gain an advantage militarily or to make life easier. Military usage seems to be a driving factor, but it is not the only factor.
Guerilla tactics played an even greater part in the US conflict in Iraq and Afghanistan. Using lessons learned fighting the Soviets in the 1980s and training from US backed anti-Soviet forces, the guerilla tactics did increasing damage to US military forces. Insurgents...
Stability or insanity
I've just spent over two weeks getting ready to do my next video. It was a combination of one of those vast underestimations one occasionally makes, combined with falling into a bit of an obsession.
I am, at this point, not only wondering if it was worth it, but questioning my sanity in carrying on even when the going went beyond tough to just plain crazy.
At any rate, a good video needs a visual aid, and I decided that my video needed to demonstrate stability with a pendulum....
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...
Optimizing Optoisolators, and Other Stories of Making Do With Less
It’s been a few months since I’ve rolled up my sleeves here and dug into some good old circuit design issues. I started out with circuit design articles, and I’ve missed it.
Today’s topic will be showing you some tricks for how to get more performance out of an optoisolator. These devices — and I’m tempted to be lazy and call them “optos”, but that sounds more like a cereal with Greek yogurt-covered raisins — are essentially just an LED...
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...
Arduino robotics #2 - chassis, locomotion and power
Arduino Robotics
Beginner robotics is a series of article chronicling my first autonomous robot build, Clusterbot. This build is meant to be affordable, relatively easy and instructive. The total cost of the build is around $50.
1. Arduino robotics - motor control2. Arduino robotics - chassis, locomotion and power3. Arduino robotics - wiring, coding and a test run4.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...
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...
Review: Project Management for the Unofficial Project Manager
Software development projects are notorious for having problems. Late, over budget, not working properly, making people's lives miserable all around. Embedded systems add the further complication of hardware to that.
How many of us have lived through problematic projects? Hopefully some of them have at least been ultimately successful to make all the suffering worth it in the end, but there are plenty that haven't.
I don't consider myself a project manager, or a manager...
Five ‘80s Movies that Inspired Me to Become an Engineer
Five ‘80s Movies that Inspired Me to Become an Engineer
Movies and pop culture can incredibly impact society, particularly children. However, we never really know what conversation, demonstration, or movie could inspire someone to become an engineer. Recently in the Beningo house, we ran out of the film to watch for movie night. In desperation, I decided to find great movies from my childhood in the 80s. To my surprise, I realized how influential several of these films inspired me 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.
Introducing the VPCIe framework
Introduction
My daily work involves platforms featuring an embedded CPU communcating with a FPGA device over a PCI Express link (PCIe for short). The main purpose of this link is for the CPU to convey configuration, control, and status commands to hardware slaves implemented in the FPGA. For data intensive applications (2D XRay detector readout backend), this link can also be used as a DMA channel to transfer data from the FPGA to the CPU memory. Finally, a slave can interrupt the CPU using...
Polynomial Inverse
One of the important steps of computing point addition over elliptic curves is a division of two polynomials.
Ten Little Algorithms, Part 7: Continued Fraction Approximation
In this article we explore the use of continued fractions to approximate any particular real number, with practical applications.
One Clock Cycle Polynomial Math
Error correction codes and cryptographic computations are most easily performed working with GF(2^n)
Acceptance Tests vs. TDD
Contents:Call for Bloggers!
Are you passionate about embedded systems? Do you have valuable insights, tips, or stories to share with the embedded community? Do you want to reach a large and engaged audience of embedded enthusiasts and professionals? We are currently looking at adding a few more inspired writers to our team of bloggers.
Dumb Embedded System Mistakes: Running The Wrong Code
ContentsA 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...Get your microcontroller and PC to talk
(and get it done free ‘n’ easy!)
The Need
Specifications can dynamically change during the product development cycle. Bosses/clients suddenly approach us with additional requirements, which, however simple, can put us in a fix. One such requirement could be to have a PC based design interface for a standalone microcontroller project.
On many occasions, the required PC software has to just behave like a slave...
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...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,...
Embedded Toolbox: Windows GUI Prototyping Toolkit
In this installment of my "Embedded Toolbox" series, I would like to interest you in the free Windows GUI Toolkit called QWin for prototyping, developing and debugging embedded C or C++ code on Windows.
If you work on devices with non-trivial user interfaces consisting of LCDs (segmented or graphic), buttons, LEDs, etc., QWin could be just the tool for you. It has improved my productivity in such projects dramatically. I personally consider it a gem in my "Embedded...
