Kind of Buggy! The state machine fantastic//
Over the years, I have had the opportunity to experience a lot of different kinds of coding mistakes. There were many that most programmers are familiar with, counting errors, indexing errors (the infamous 'off by one' bug), memory space sharing errors (A threading issue) as well as numerous others. I ran into one recently that I wound up using an old trick to help find.
My current project is a Pan/Tilt camera that was, upon occasion, not homing properly in one axis. The camera is a...
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...
Deeply embedded design example - Logic replacement
I have always believed that some of the low-cost, low-pin count, low-resource microprocessors would make an excellent choice for the replacement of discrete logic components. In these cases the deeply embedded microprocessor would become less of a general purpose computer and more of a logic replacement, providing a prescribed function with no connection to the outside world. In a world of bigger, faster and more expensive, it is a pleasant change of pace...
Embedded Software Creation I - Methodologies
The first knowledge we need it is to know the posibilities or methodologies that exists to create Software. Each methodology is used to develop diferent types of Software. The types usually are defined by the requeriments and the diferent normative that is related to the type of device. In the next post I will explain how to find the normative@ legislation (link), and how does it work.
Let's start with methodologies. There are lot's of methodologies and so many people that develop...
VHDL tutorial - A practical example - part 2 - VHDL coding
In part 1 of this series we focused on the hardware design, including some of the VHDL definitions of the I/O characteristics of the CPLD part. In part 2, we will describe the VHDL logic of the CPLD for this design.
With any design, the first step to gather the requirements for the job at hand. From part 1 of this article, I have copied two sections that address some of the requirements for the CPLD design.
The data acquisition engine has the...
Tracing code and checking timings
Debugging resource limited systemsApplications writers that write code on large systems have it easy. Well, perhaps not easy, but certainly easier. There are some things that they don't have to worry about and there is a huge array of tools available to them when it comes time to debug. The have choices in their toolsets, lots of choices. They also have a large selection of available methods for getting debugging information out to them such as log files, proc entries, pop up dialog boxes or...
It starts with an LED
And slowly builds up from there.
I have been an embedded software engineer for many years. I was programming when I was a teenager before then, as a high school student involved in an NSF program called "National Science Foundation Summer Science Training Program (for High School Students)" or as we would rattle off during that summer of exquisite learning, NSFSSTP. We were taught to program in Fortran and taught the fundamentals of Calculus. It was a very enriching experience.
When it...
Size matters - System success depends on initial design
Too many times during the initial phases of system design, opposing interests start fighting for valuable resources, sometimes without even knowing that they are. Case in point, a development project is starting up with a very simple product. For the user interface, Engineering wants to use a very simple character based LCD display and a couple of membrane switches, while Marketing wants a graphic display with a touch screen. The cost difference between these two items is...
Software Prototyping
In my recent blog entry on the product development process (way down, near the end of the entry), I wrote the following:
"I continue these sorts of tests, building more and more complexity, until I am satisfied that my circuit is basically functional. Then, using the test code that I have created as a model, I begin to write the real software for my product. As my software grows, to complete the full functionality of my design, I sometime find it useful to drop back to my 'test software'...
Bringing up Baby - product development thoughts
Things have just started to get exciting. After months of defining, specifying and designing my latest product, I finally have semi-functional prototypes. After a few side steps during the building and bring-up process, power is applied and most of the low level functions have been verified. Soon, software will meet hardware and debugging can begin in earnest.
Before jumping in and really enjoying the fun (besides I'm now waiting for some new parts to arrive), I thought it would be nice to...
Bringing up Baby - product development thoughts
Things have just started to get exciting. After months of defining, specifying and designing my latest product, I finally have semi-functional prototypes. After a few side steps during the building and bring-up process, power is applied and most of the low level functions have been verified. Soon, software will meet hardware and debugging can begin in earnest.
Before jumping in and really enjoying the fun (besides I'm now waiting for some new parts to arrive), I thought it would be nice to...
Software Prototyping
In my recent blog entry on the product development process (way down, near the end of the entry), I wrote the following:
"I continue these sorts of tests, building more and more complexity, until I am satisfied that my circuit is basically functional. Then, using the test code that I have created as a model, I begin to write the real software for my product. As my software grows, to complete the full functionality of my design, I sometime find it useful to drop back to my 'test software'...
You Will Make Mistakes
</scorpion>: FAIL
Anyone out there see the TV pilot of Scorpion? Genius hacker squad meets Homeland Security in a fast-paced thriller to save hundreds of airplanes from crashing after LAX air traffic control software upgrade fails and they didn’t save a backup of the old version (ZOMG!!!) so thousands of people are going to die because the planes… well, they just can’t land! They just can’t. Even if the weather is sunny and calm and there could quite possibly...
The three laws of safe embedded systems
This short article is part of an ongoing series in which I aim to explore some techniques that may be useful for developers and organisations that are beginning their first safety-related embedded project.
In the last two weeks, I’ve had the opportunity to discuss the contents of my previous article on this site with a group of very smart and enthusiastic engineers in Cairo (Egypt). As part of this discussion, it has become clear that I should add a few more details to explain the work...
Building Linux Kernel for Desktops
Linux Development has made an amazing process in last decade. Different Linux Distributions come with specific tools which greatly ease down the build process for Linux Kernel.
Here is a good introduction to these build tools and build procedure for different Linux Distributions:
Size matters - System success depends on initial design
Too many times during the initial phases of system design, opposing interests start fighting for valuable resources, sometimes without even knowing that they are. Case in point, a development project is starting up with a very simple product. For the user interface, Engineering wants to use a very simple character based LCD display and a couple of membrane switches, while Marketing wants a graphic display with a touch screen. The cost difference between these two items is...
Kind of Buggy! The state machine fantastic//
Over the years, I have had the opportunity to experience a lot of different kinds of coding mistakes. There were many that most programmers are familiar with, counting errors, indexing errors (the infamous 'off by one' bug), memory space sharing errors (A threading issue) as well as numerous others. I ran into one recently that I wound up using an old trick to help find.
My current project is a Pan/Tilt camera that was, upon occasion, not homing properly in one axis. The camera is a...
Lightweight hardware abstraction
Some lessons are tougher than others to master. You would think that hard fought battles would be easier to remember, but sometimes it just does not work that way. Recently, I was asked to pick-up a project that had been managed by another employee. The project was yet another cost reduction project. The hardware group was tasked with updating a currently shipping product, to reduce the existing failure rate, while at the same time to remove cost from the...
Is it a Bug or an Error?
Probably you’ve heard the story of how Adm. Grace Hopper attached a moth that was dislodged from a relay in the Harvard Mark II mainframe to an engineering notebook and labeled it the “First actual case of bug being found.”
Designers of electronics, including Thomas Edison, had been using the term bug for decades. But it was mostly after this amusing 1947 event hat the use of words like “bugs” and “debugging” took off in the emerging software realm.
So why is it that if a...
Hello Android
Finally I could get Android Early SDK up and running on my Fedora Core-7 Machine.
The process was quite simple. However I had to struggle for a few days, because Fedora install the gnu version of Java and Android requires Java from Sun.
Here are the steps I had to follow:
(1) Install the eclipse IDE (if you do not have it already) with following command:
$> yum install eclipse-jdt eclipse-jdt-sdk (to be done as super user).
(2) now install the Android SDK and ADT plug-in for Eclipse...
A true pioneer passes away... A farewell to Ritchie.
We all have our heroes. We all have people who were important to our professional developments. For me, Dennis Ritchie was one of those people. I was an early adopter of the C programming language. Back in the very early 80's a friend and neighbor had excitedly shared with me his copy of "The C Programming Language" by Kernighan and Ritchie. At first I was a non-believer. I had for several years been a happy and productive assembly language...
UML Statechart tip: Handling errors when entering a state
This is my second post with advice and tips on designing software with UML statecharts. My first entry is here.
It has been nearly 20 years since I first studied UML statecharts. Since that initial exposure (thank you Samek!), I have applied event driven active object statechart designs to numerous projects [3]. Nothing has abated my preference for this pattern in my firmware and embedded software projects. Through the years I have taken note of a handful of common challenges when...
Debugging DSP code.
I am fascinated with neural network processing and have been playing with them since the 80's.
I am a frequent contributor to the Numenta forum. Numenta is the current project of Jeff Hawins, the guy that gave us the Palm Pilot. They are working with the HTM model. This is a system based on studies of the functions of the cortical column and has some very interesting properties: It processes sequential data streams and has very effective one shot learning. The data is arranged in Sparse...
Building Linux Kernel for Desktops
Linux Development has made an amazing process in last decade. Different Linux Distributions come with specific tools which greatly ease down the build process for Linux Kernel.
Here is a good introduction to these build tools and build procedure for different Linux Distributions:
Tracing code and checking timings
Debugging resource limited systemsApplications writers that write code on large systems have it easy. Well, perhaps not easy, but certainly easier. There are some things that they don't have to worry about and there is a huge array of tools available to them when it comes time to debug. The have choices in their toolsets, lots of choices. They also have a large selection of available methods for getting debugging information out to them such as log files, proc entries, pop up dialog boxes or...
Size matters - System success depends on initial design
Too many times during the initial phases of system design, opposing interests start fighting for valuable resources, sometimes without even knowing that they are. Case in point, a development project is starting up with a very simple product. For the user interface, Engineering wants to use a very simple character based LCD display and a couple of membrane switches, while Marketing wants a graphic display with a touch screen. The cost difference between these two items is...
Bringing up Baby - product development thoughts
Things have just started to get exciting. After months of defining, specifying and designing my latest product, I finally have semi-functional prototypes. After a few side steps during the building and bring-up process, power is applied and most of the low level functions have been verified. Soon, software will meet hardware and debugging can begin in earnest.
Before jumping in and really enjoying the fun (besides I'm now waiting for some new parts to arrive), I thought it would be nice to...
It starts with an LED
And slowly builds up from there.
I have been an embedded software engineer for many years. I was programming when I was a teenager before then, as a high school student involved in an NSF program called "National Science Foundation Summer Science Training Program (for High School Students)" or as we would rattle off during that summer of exquisite learning, NSFSSTP. We were taught to program in Fortran and taught the fundamentals of Calculus. It was a very enriching experience.
When it...
Hello Android
Finally I could get Android Early SDK up and running on my Fedora Core-7 Machine.
The process was quite simple. However I had to struggle for a few days, because Fedora install the gnu version of Java and Android requires Java from Sun.
Here are the steps I had to follow:
(1) Install the eclipse IDE (if you do not have it already) with following command:
$> yum install eclipse-jdt eclipse-jdt-sdk (to be done as super user).
(2) now install the Android SDK and ADT plug-in for Eclipse...
Welcome to my life!
Hi folks!
As an electronic engineer the most of my work is about making new designs where a microcontroller is present in 99.9 % of the applications. Since 2003 I am self-employed and do consultants work for different companies. I have been traveling to different parts of the world doing work for DeLaval International, a company that makes automation equipment for the dairy industry. A lot of the things I have done for them involves use of different Atmel AVR...
