EmbeddedRelated.com

Zephyr: West Manifest For Application Development

Mohammed Billoo November 25, 2024

In this blog post, I show a simpler way to create custom West manifest files. This technique eliminates the need to duplicate the complex West manifest from upstream Zephyr. I also show how we can use the West manifest to include out-of-tree board and SoC definitions, and include our own out-of-tree drivers.


Simulating Your Embedded Project on Your Computer (Part 2)

Nathan Jones November 4, 2024

Having a simulation of your embedded project is like having a superpower that improves the quality and pace of your development ten times over! To be useful, though, it can't take longer to develop the simulation than it takes to develop the application code and for many simulation techniques "the juice isn't worth the squeeze"! In the last article, I showed you how to use the terminal (i.e. printf/getchar) to easily make a completely functional simulation. In this article, we'll take simulation to the next level, either in terms of realism (by using virtual hardware) or in terms of user experience (by using a GUI to simulate our hardware, instead of using the terminal).


In TCL FPGA Wizards Trust

GLENN Kirilow October 16, 2024

In TCL FPGA wizards trust. The best way to learn TCL is exposure therapy which we will be doing here using two examples: One for creation of a project with synthesis and implementation steps and another for simulation.


Product quality: belief or proof?

Colin Walls October 7, 2024

Embedded software development is a challenging activity, so it is essential to have tools and IP that is of the best quality. However, assessing that quality can be, in itself, a challenge.


Simulating Your Embedded Project on Your Computer (Part 1)

Nathan Jones October 2, 20242 comments

Having a simulation of your embedded project is like having a superpower that improves the quality and pace of your development ten times over! To be useful, though, it can't take longer to develop the simulation than it takes to develop the application code and for many simulation techniques "the juice isn't worth the squeeze"! In this two-part blog series, I'll share with you the arguments in favor of simulation (so, hopefully, you too believe in its value) and I'll show you what works (and what doesn't work) to help you to simply, easily, and quickly simulate your embedded project on your computer.


Understanding Yocto Project Layers: A Modular Approach to Embedded Systems Development

Aaksha Jaywant September 16, 2024

In the world of embedded systems, flexibility and modularity are key to managing complex projects efficiently. The Yocto Project, a powerful build system for creating custom Linux distributions, embraces this philosophy through the use of layers. These layers are essentially sets of repositories that contain the instructions and metadata required to build a specific target image. By leveraging layers, developers can modularize their projects, reusing and sharing previously developed metadata...


Small or fast?

Colin Walls August 26, 20244 comments

Developers of software for desktop computers take code optimization for granted. Embedded developers typically need to pay much more attention to the details


Stand-by or boot-up

Colin Walls August 8, 2024

Many factors affect the usability of devices - a key one is how long it takes to start up.


Write Better Code with Block Diagrams and Flowcharts

Nathan Jones August 1, 20241 comment

Reading and writing code without architectural diagrams is like trying to follow complex instructions without any explanatory pictures: nigh impossible! By taking the time to draw out the block diagrams and flowcharts for your code, you can help identify problems before they arise and make your code easier to design, write, test, and debug. In this article, I'll briefly justify the importance of architectural drawings such as block diagrams and flowcharts and then teach you what they are and how to draw them. Using two simple examples, you'll see first-hand how these drawings can significantly amplify your understanding of a piece of code. Additionally, I'll give you a few tips for how to implement each drawing once you've completed it and I'll share with you a few neat tools to help you complete your next set of drawings.


Some Embedded System Software Design Resources

Steve Branam July 23, 2024

I recently received a message from an embedded systems engineer in England asking about a good resource for embedded system software design and easing debugging difficulties.

That's challenging because embedded systems cover such a wide range. There are many possible run-time environments and architectures.

Thus there's no single resource that covers all ground. However, the resources below provide a lot of good material. In aggregate, they make up a good set from which to pull various...


Analyzing the Linker Map file with a little help from the ELF and the DWARF

Govind Mukundan December 27, 201524 comments

When you're writing firmware, there always comes a time when you need to check the resources consumed by your efforts - perhaps because you're running out of RAM or Flash or you want to optimize something. The map file generated by your linker is a useful tool to aid in the resource analysis. I wanted to filter and sort the data generated in an interactive way so I wrote a C# WinForms application that reads the data from the map and presents it in a list view (using the awesome


Chebyshev Approximation and How It Can Help You Save Money, Win Friends, and Influence People

Jason Sachs September 30, 201220 comments

Well... maybe that's a stretch. I don't think I can recommend anything to help you win friends. Not my forte.

But I am going to try to convince you why you should know about Chebyshev approximation, which is a technique for figuring out how you can come as close as possible to computing the result of a mathematical function, with a minimal amount of design effort and CPU power. Let's explore two use cases:

  • Amy has a low-power 8-bit microcontroller and needs to compute \( \sqrt{x} \)...

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

Jason Sachs 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: ...

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


Using the Beaglebone PRU to achieve realtime at low cost

Fabien Le Mentec April 25, 20148 comments
Introduction

I work as an engineer in a synchrotron facility. A few weeks ago, I helped the people in charge of the power supply developments to integrate a realtime control algorithm on a prototype platform: a BeagleBone Black (BBB) running Linux. I had already worked with this board in the past, and I found it very interesting given its excellent resources versus price ratio (around 40 euros). This time, I was impressed by its realtime capabilities. I thought it would be a good idea to...


Coroutines in one page of C

Yossi Kreinin August 20, 201315 comments

A coroutine is a function that you can jump back into after returning from it - and it remembers where it was in the code, and all the variables. This is very useful at times.

One use is generating a sequence of values. Here's how you can generate all the x,y pairs in a 2D range in Python:

def iterate(max_x, max_y): for x in range(max_x): for y in range(max_y): yield x,y for x,y in iterate(2,2): print x,y

This prints:

0 0 0 1 1 0 1 1

The yield keyword is like...


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

Jason Sachs August 26, 20145 comments

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...


Using the C language to program the am335x PRU

Fabien Le Mentec June 7, 201481 comments
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...


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

Wouter van Ooijen October 9, 20117 comments

 

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...