How to Give Persistent Names To USB-Serial Devices on Ubuntu 14.04

Dr. Tayyar GUZEL May 22, 20171 comment

If you have a bunch of USB-serial devices connected to your dock station and you needed to bind your USB-serial devices under static names so that all the USB-serial devices don't get to be assigned to random names by "udev" manager when you re-plug your laptop to the dock station, follow the instructions below. I will share the udev rules I created as a reference and give the step by step instructions to achieve persistent naming. All the steps worked on my Ubuntu 14.04...


Tenderfoot: Introduction to Magic (Numbers that is...)

Matthew Eshleman May 10, 20171 comment

Once upon a time, while participating in a source code review, I stumbled across the following C code in a header file:

struct Foo { //various structure fields char string_buffer[45+3]; //buffer requires about 45 bytes };

My right eyebrow raised, I took a note, and continued with the code review, only to later stumble into this line of code in the body of a C function:

char * temp_string_buffer = (char*) malloc(45+3);

Again, I took a note on this function, and continued...


Back from ESC Boston

Stephane Boucher May 7, 20172 comments

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

Jason Sachs April 17, 20172 comments

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;DR

The 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

Stephane Boucher April 5, 201721 comments

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

Ed Nutter March 29, 2017

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)

Jason Sachs February 27, 20171 comment

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

Matthew Eshleman February 27, 2017

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?

Stephane Boucher 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...


My little runaway...

Ed Nutter January 19, 2017

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...


Data Hiding in C

Stephen Friederichs April 21, 201317 comments

Strictly speaking, C is not an object-oriented language. Although it provides some features that fit into the object-oriented paradigm it has never had the full object-oriented focus that its successor C++ offers. C++ introduced some very useful concepts and abilities that I miss when I’m developing in ANSI C. One such concept is protected member variables and functions.

When you declare a class in C++ you can also declare member variables and functions as part of that class. Often, these...


Byte and Switch (Part 1)

Jason Sachs April 27, 201112 comments

Imagine for a minute you have an electromagnet, and a microcontroller, and you want to use the microcontroller to turn the electromagnet on and off. Sounds pretty typical, right?We ask this question on our interviews of entry-level electrical engineers: what do you put between the microcontroller and the electromagnet?We used to think this kind of question was too easy, but there are a surprising number of subtleties here (and maybe a surprising number of job candidates that were missing...


Zebras Hate You For No Reason: Why Amdahl's Law is Misleading in a World of Cats (And Maybe in Ours Too)

Jason Sachs February 27, 20171 comment

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


Arduino robotics #1 - motor control

Lonnie Honeycutt October 13, 20132 comments
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. 

Embedded Toolbox: Programmer's Calculator

Miro Samek June 27, 20178 comments

Like any craftsman, I have accumulated quite a few tools during my embedded software development career. Some of them proved to me more useful than others. And these generally useful tools ended up in my Embedded Toolbox. In this blog, I'd like to share some of my tools with you. Today, I'd like to start with my cross-platform Programmer's Calculator called QCalc.

I'm sure that you already have your favorite calculator online or on your smartphone. But can your calculator accept...


Ten Little Algorithms, Part 1: Russian Peasant Multiplication

Jason Sachs March 22, 20155 comments

This blog needs some short posts to balance out the long ones, so I thought I’d cover some of the algorithms I’ve used over the years. Like the Euclidean algorithm and Extended Euclidean algorithm and Newton’s method — except those you should know already, and if not, you should be locked in a room until you do. Someday one of them may save your life. Well, you never know.

Other articles in this series:

  • Part 1:

Boot sequence for an ARM based embedded system -2

DM April 6, 201212 comments

In the last post, we discussed about the startup execution sequence on an ARM based embedded system in broader terms. In this post, we are going to cover the details of a startup code.These details are also available through various ARM resources , however for the sake of completion of our discussion , here is - the flow the startup code for an  ARM based embedded system.

 Step 1: The reset

On startup, the processor will jump to fixed location ,(most ARM cores support two vector...


VHDL tutorial - Creating a hierarchical design

Gene Breniman May 22, 20086 comments

In earlier blog entries I introduced some of the basic VHDL concepts. First, developing a function ('VHDL tutorial') and later verifying and refining it ('VHDL tutorial - part 2 - Testbench' and 'VHDL tutorial - combining clocked and sequential logic'). In this entry I will describe how to...


Analog-to-Digital Confusion: Pitfalls of Driving an ADC

Jason Sachs November 19, 20115 comments

Imagine the following scenario:You're a successful engineer (sounds nice, doesn't it!) working on a project with three or four circuit boards. More than even you can handle, so you give one of them over to your coworker Wayne to design. Wayne graduated two years ago from college. He's smart, he's a quick learner, and he's really fast at designing schematics and laying out circuit boards. It's just that sometimes he takes some shortcuts... but in this case the circuit board is just something...


Important Programming Concepts (Even on Embedded Systems) Part V: State Machines

Jason Sachs January 5, 20158 comments

Other articles in this series:

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...