Embedded Toolbox: Source Code Whitespace Cleanup

Miro Samek August 5, 2017

In this installment of my "Embedded Toolbox" series, I would like to share with you the free source code cleanup utility called QClean for cleaning whitespace in your source files, header files, makefiles, linker scripts, etc.

You probably wonder why you might need such a utility? In fact, the common thinking is that compilers (C, C++, etc.) ignore whitespace anyway, so why bother? But, as a professional software developer you should not ignore whitespace, because it can cause all sorts...


Embedded Toolbox: Windows GUI Prototyping Toolkit

Miro Samek July 7, 20172 comments

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...


Tenderfoot: Recommended Reading

Matthew Eshleman June 28, 20171 comment

Twenty years ago I read Code Complete by Steve McConnell. And then read it again. And again. And again. Of all the books I have read during my career, I believe this was the book that catapulted me from a young electrical engineer to a young and aspiring embedded software engineer. So to all the ‘tenderfoots’ embarking upon an embedded systems and especially embedded software and firmware career, this entry is for you.

First, I would certainly recommend that all engineers read and read...


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...


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

Matthew Eshleman May 10, 20173 comments

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...


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...


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 26, 20172 comments

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...


Vala applications on Embedded Linux: maybe a clever choice [part 1]

Felipe Lavratti December 19, 2016

Vala is a sexy, open source, high level programming language that appeared in 2006, it counts with a modern typing system, is object oriented, compiled and statically typed, it has a almost identical syntax to C# and is maintained by GNOME. The language was created as a power abstraction of the GLib and GTK libraries, two considerably lightweight and powerful libraries written in C, and it is used in projects such as GNOME Clocks, Shotwell, GXml and Elementary OS.

namespace...

Favorite Tools: C++11 User-defined literals

Matthew Eshleman November 14, 20161 comment

In many software domains units of measurement are frequently critical to the software's data processing requirements. Those same units, or rather the use of the wrong units, are often the source of bugs and disastrous mistakes. Although useful for other purposes, user-defined literals are an excellent addition to the C++11 standard and handy when working with units of measurement.

Suppose a device measures velocity. To help prevent errors, the software specification requires...


Android for Embedded Devices - 5 Reasons why Android is used in Embedded Devices

Maharajan Veerabahu November 6, 20173 comments

The embedded purists are going to hate me for this. How can you even think of using Android on an embedded system ? It’s after all a mobile phone operating system/software. 

Sigh !! Yes I did not like Android to begin with, as well - for use on an Embedded System. But sometimes I think the market and needs decide what has to be used and what should not be. This is one such thing. Over the past few years, I have learned to love Android as an embedded operating system....


Important Programming Concepts (Even on Embedded Systems) Part II: Immutability

Jason Sachs September 14, 2014

Other articles in this series:

This article will discuss immutability, and some of its variations in the topic of functional programming.

There are a whole series of benefits to using program variables that… well, that aren’t actually variable, but instead are immutable. The impact of...


From bare-metal to RTOS: 5 Reasons to use an RTOS

Jacob Beningo October 18, 20167 comments

Developers can come up with amazing and convoluted reasons to not use an RTOS. I have heard excuses ranging from they are too expensive (despite open source solutions) all the way to they aren’t efficient and use too much memory. In some circumstances some excuses are justified but there are many reasons why a developer should look to an RTOS to help with their real-time scheduling needs.

From bare-metal to RTOS Quick Links
  • Part 1: 

C Programming Techniques: Function Call Inlining

Fabien Le Mentec April 29, 20137 comments
Introduction

Abstraction is a key to manage software systems as they increase in size and complexity. As shown in a previous post, abstraction requires a developper to clearly define a software interface for both data and functions, and eventually hide the underlying implementation.When using the C language, the interface is often exposed in a header '.h' file, while the implementation is put in one or more  corresponding '.c' files.

First, separating an interface from its...


Coding Step 1 - Hello World and Makefiles

Stephen Friederichs February 10, 20156 comments

Articles in this series:

Step 0 discussed how to install GCC and the make utility with the expectation of writing and compiling your first C program. In this article, I discuss how to use those tools we installed last time. Specifically, how to use GCC to compile a C program and...


Lazy Properties in Python Using Descriptors

Jason Sachs November 7, 2017

This is a bit of a side tangent from my normal at-least-vaguely-embedded-related articles, but I wanted to share a moment of enlightenment I had recently about descriptors in Python. The easiest way to explain a descriptor is a way to outsource attribute lookup and modification.

Python has a bunch of “magic” methods that are hooks into various object-oriented mechanisms that let you do all sorts of ridiculously clever things. Whether or not they’re a good idea is another...


Coding - Step 0: Setting Up a Development Environment

Stephen Friederichs November 25, 20145 comments

Articles in this series:

You can easily find a million articles out there discussing compiler nuances, weighing the pros and cons of various data structures or discussing the  optimization of databases. Those sorts of articles are fascinating reads for advanced programmers but...


Cortex-M Exception Handling (Part 1)

Ivan Cibrario Bertolotti November 28, 20152 comments

This article describes how Cortex-M processors handle interrupts and, more generally, exceptions, a concept that plays a central role in the design and implementation of most embedded systems. The main reason of discussing this topic in detail is that, in the past few years, the degree of sophistication (and complexity) of microcontrollers in handling interrupts steadily increased, bringing them on a par with general-purpose processors.


OOKLONE: a cheap RF 433.92MHz OOK frame cloner

Fabien Le Mentec August 12, 201417 comments
Introduction

A few weeks ago, I bought a set of cheap wireless outlets and reimplemented the protocol for further inclusion in a domotics platform. I wrote a post about it here:

//www.embeddedrelated.com/showarticle/620.php

Following that, I had access to another outlet from a different vendor:

http://www.castorama.fr/store/Prise-telecommandee-BLYSS---Interieur-prod4470027.html

The device documentation mentions that it operates on the same frequency as the previous...


The CRC Wild Goose Chase: PPP Does What?!?!?!

Jason Sachs October 23, 20142 comments

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,...