February 5, 2019

## Embedded Programming Video Course Teaches RTOS

January 20, 2019

If you'd like to understand how a Real-Time Operating System (RTOS) really works, here is a free video course for you:

RTOS part-1: In this first lesson on RTOS you will see how to extend the foreground/background architecture from the previous lesson, so that you can have multiple background loops running seemingly simultaneously.:

RTOS part-2: In this second lesson on RTOS you will see how to automate the context switch process. Specifically, in this lesson, you will start building...

## The Hardest Bug I Never Solved

I agreed to four hours.

Four hours to help hunt down and kill a bug. A terrible malicious bug that was eating away at this project, wreaking havoc upon the foundations of a critical feature, and draining time randomly from every one of eight firmware engineers on this project. Quite honestly, I can’t remember the last time it took more than an hour or two for me to locate, isolate, and fix a firmware bug. Surely I could help find and solve this issue within four...

## Wye Delta Tee Pi: Observations on Three-Terminal Networks

December 23, 2018

Today I’m going to talk a little bit about three-terminal linear passive networks. These generally come in two flavors, wye and delta.

Why Wye?

The town of Why, Arizona has a strange name that comes from the shape of the original road junction of Arizona State Highways 85 and 86, which was shaped like the letter Y. This is no longer the case, because the state highway department reconfigured the intersection

## The Least Interesting Circuit in the World

It does nothing, most of the time.

It cannot compute pi. It won’t oscillate. It doesn’t light up.

Often it makes other circuits stop working.

It is… the least interesting circuit in the world.

What is it?

About 25 years ago, I took a digital computer architecture course, and we were each given use of an ugly briefcase containing a bunch of solderless breadboards and a power supply and switches and LEDs — and a bunch of

## Servo Troubleshooting notes

October 4, 2018

Servo Troubleshooting

Ostendorff

Forcing a servo to rotate when off can damage it.

Malfunction:Servo makes a grinding noise or acts erratic

Probable Cause

Corrective Action

Source

Examine gears for broken teeth

Replace gears

General

Malfunction:Servo Jitters

Probable Cause

Corrective Action

Source

Dirty potentiometer

...

## Linear Feedback Shift Registers for the Uninitiated, Part XVIII: Primitive Polynomial Generation

August 6, 20181 comment

Last time we figured out how to reverse-engineer parameters of an unknown CRC computation by providing sample inputs and analyzing the corresponding outputs. One of the things we discovered was that the polynomial $x^{16} + x^{12} + x^5 + 1$ used in the 16-bit X.25 CRC is not primitive — which just means that all the nonzero elements in the corresponding quotient ring can’t be generated by powers of $x$, and therefore the corresponding 16-bit LFSR with taps in bits 0, 5,...

## 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...

## R1C1R2C2: The Two-Pole Passive RC Filter

July 28, 20181 comment

I keep running into this circuit every year or two, and need to do the same old calculations, which are kind of tiring. So I figured I’d just write up an article and then I can look it up the next time.

This is a two-pole passive RC filter. Doesn’t work as well as an LC filter or an active filter, but it is cheap. We’re going to find out a couple of things about its transfer function.

First let’s find out the transfer function of this circuit:

Not very...

## Linear Feedback Shift Registers for the Uninitiated, Part XVII: Reverse-Engineering the CRC

July 7, 20181 comment

Last time, we continued a discussion about error detection and correction by covering Reed-Solomon encoding. I was going to move on to another topic, but then there was this post on Reddit asking how to determine unknown CRC parameters:

I am seeking to reverse engineer an 8-bit CRC. I don’t know the generator code that’s used, but can lay my hands on any number of output sequences given an input sequence.

This is something I call the “unknown oracle”...

## Using the C language to program the am335x PRU

Introduction

Some weeks ago, I published an article on how we used the PRU to implement a power supply control loop having hard realtime constraints:

//www.embeddedrelated.com/showarticle/586.php

Writing this kind of logic in assembly language is not easy. First the assembly language itself may be difficult to learn depending on your background. Then, fixed and floating point arithmetics require lot of code. While macros help to handle the complexity, they still are error prone as you...

## Boot Sequence for an ARM based embedded system

Hello all,

Allow me to introduce myself. I am Deeksha and I come from plains of North India. My tryst with embedded technologies has been 5 years long and every single day I am amazed with the vastness and learning involved. The thing with embedded technologies is either you are into it, or you aren't. You cannot just hang around half-heartedly (I guess that holds true for every field, for that matter).You have to keep the learning and sharing process going on. And that is the reason I am...

## 10 Software Tools You Should Know

Unless you're designing small analog electronic circuits, it's pretty hard these days to get things done in embedded systems design without the help of computers. I thought I'd share a list of software tools that help me get my job done. Most of these are free or inexpensive. Most of them are also for working with software. If you never have to design, read, or edit any software, then you're one of a few people that won't benefit from reading this.

Disclaimer: the "best" software...

## Introduction to Microcontrollers - Hello World

Embedded Hello World

A standard first program on an embedded platform is the blinking LED.  Getting an LED to blink demonstrates that you have your toolchain set up correctly, that you are able to download your program code into the μC, and that the μC and associated circuitry (e.g. the power supply) is all working.  It can even give you good evidence as to the clock rate that your microcontroller is running (something that trips up a great many people,...

## Important Programming Concepts (Even on Embedded Systems) Part I: Idempotence

There are literally hundreds, if not thousands, of subtle concepts that contribute to high quality software design. Many of them are well-known, and can be found in books or the Internet. I’m going to highlight a few of the ones I think are important and often overlooked.

But first let’s start with a short diversion. I’m going to make a bold statement: unless you’re a novice, there’s at least one thing in computer programming about which you’ve picked up...

## Understanding and Preventing Overflow (I Had Too Much to Add Last Night)

December 4, 2013

Happy Thanksgiving! Maybe the memory of eating too much turkey is fresh in your mind. If so, this would be a good time to talk about overflow.

In the world of floating-point arithmetic, overflow is possible but not particularly common. You can get it when numbers become too large; IEEE double-precision floating-point numbers support a range of just under 21024, and if you go beyond that you have problems:

for k in [10, 100, 1000, 1020, 1023, 1023.9, 1023.9999, 1024]: try: ...

## VHDL tutorial

When I was first introduced to "Programmable Logic" several years ago, it was an answer to many of the challenges that I was struggling with. Though the parts were primitive by today's standards (simple PALs verses FPGA), they were an extremely cost effective tool addressing the need for specialized logic blocks.

I have continued to incorporate these powerful blocks into many of my latest designs. My current favorite part line is the Xilinx CoolRunner series (XC2Cxxx). In this...

## An overview of Linux Boot Process for Embedded Systems

This Text provides an insight in to the Embedded Linux Boot Process. Reader should have a basic Knowledge of Boot Process in general and should be familiar with Embedded Linux Boot Process.

.................PART-A................(1) Software components Involved in Embedded Linux Boot Process    (a) Bootloader    (b) kernel Image    (c) root file system - either an initrd image or a NFS location(2) Steps during Booting process of a conventional...

## C++ on microcontrollers 1 - introduction, and an output pin class

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 am lazy. I am also a programmer. Luckily, being a lazy...

## Introduction to Microcontrollers - Further Beginnings

Embedded Programming Basics

This tutorial entry will discuss some further embedded programming basics that you will need to understand before proceeding on to the LED blinky and other example programs. We will do this by looking at the general organization and types of instructions found in most microcontrollers, and how that organization and those instructions are reflected (or, in some cases, ignored) by the C programming language.

Basic CPU...

## ESC Boston's Videos are Now Up

June 5, 2017

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 Highlight

This 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...

## 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...

## 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...

## Who else is going to Embedded World 2017 in Nuremberg?

February 2, 20171 comment

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...

I thought it would take me a day or two to implement, it took almost two weeks...

But here it is, the new comments systems for blogs, heavily inspired by the forum system I developed earlier this year.

Which means that:

• You can easily add images, either by drag and drop or through the 'Insert Image' button
• You can add MathML, TeX and ASCIImath equations and they will be rendered with Mathjax
• You can add code snippets and they will be highlighted with highlights.js
• You can edit...

## 3 Good News

March 9, 20161 comment
Good News #1

Last week, I announced a new and ambitious reward program that will be funded by the new Vendors Directory.

This week, I am happy to announce that we have our firsts two sponsors!  Quantum Leaps & Abelon Systems have agreed to pay the sponsorship fee to be listed in the new Vendors Directory.  Because of their support, there is now some money in the reward pool (\$1,000) and enough to pay for the firsts 500 'beers' awarded.  Please...

## The New Forum is LIVE!

February 18, 20161 comment

After months of hard word, I am very excited to introduce to you the new forum interface.

Here are the key features:

1- Easily add images to a post by drag & dropping the images in the editor

2- Easily attach files to a post by drag & dropping the files in the editor

3- Add latex equations to a post and they will be rendered with Mathjax (tutorial)

4- Add a code snippet and surround the code with

## Helping New Bloggers to Break the Ice: A New Ipad Pro for the Author with the Best Article!

November 9, 2015

Breaking the ice can be tough.  Over the years, many individuals have asked to be given access to the blogging interface only to never post an article.  Maybe they underestimated the time it takes to write a decent article, or maybe they got cold feet. I don't blame or judge them at all - how many times in my life have I had the intention to do something but didn't follow through?  Once, maybe twice 😉 (don't worry if you don't...