November 30, 2012

Coding in debugger

There are posted few tips how to change immediate values, skip function call, ... during debugging. Quite helpful and I believe any embedded engineer do it regularly.

Coding in debugger []

November 29, 2012

Impulse and unit step responses

I posted yesterday post about IIR filters but totally missed the topic which I should have started with. It's about systems responses. I had finally some time to document filters we use in code.

The Unit Step Response []
Link directs to the unit step response. There's tab also with the impulse response. All explained with introduction and equations followed by pictures.
Website's name is Linear Physical System Analysis. Recommended to read !

November 28, 2012

Digital filters

I've been wondering always how to implement filter in C language. There was a time when I just copied one IIR filter and tuned it to my needs but did not bother with discovering more about it and implement my own one. This springs back when I have to test a part where are few filters applied.

I have started with IIR and low pass filters.

Fixed Point Scaling []
This one explains simple low pass filter and provides octave file which helps me really weLL.  I will come back with octave topics later.
What is moving avarage filter? []
DSPrelated is the one which I visit when I look for digital signal processing. Articles, forum with many experienced users.
Introduction to Digital Filters []

Low pass filter []
This is moving avarage filter with code. Simple which enables reader to understand it quickly.

November 27, 2012

Goto in C language

Here's another article about using goto in C language and some links to explore more. I have seen in in one RTOS and wondered back then, also with connection to error handling.

Using goto for error handling in C []

November 26, 2012

Embedded projects website

I believe I forgot this website to add to my bookmars, otherwise I would have been checking it regularly. Website has updates often. There are tutorials for AVR and ARM (STM32).

Embedded projects []

C Gotchas

I am going to post some links here about C gotchas. This one I digged today:


ARM developing with open source tools

Hello all,

my intention was to play with free available tools. I have started with CooCox 1.6.0 and Freedom Board KL25. I've had some problems with examples pregenerated, but they work and IDE works smoothly, quickly. So far not any problem except memory view, but I will figure it out somehow.
I'll post here some links about the development for free on ARM :-)

There is plug-in called Eclipse CDT Manged Build Extension for GNU ARM Toolchains like CodeSourcery G++ Lite, GNUARM, WinARM, Yagarto, devkitPro, Summon.

Free ARM CooCox IDE []
Developing with Sourcery CodeBench []
I am going to test Sourcery as second. I have to touch more peripherals in CooIDE first. []
Not only IDE to use, just command line and linux is simply enough. Here's tutorial with prerequisities and steps

November 4, 2012

Stack usage

Stack overflow? How to determine stack usage or how much dynamic allocated space does an application use? This article provides answers to those questions.

Mastering stack - Part 1[]
There are 3 parts of Mastering stack and heap written by IAR employee. Review also links at the end of the article.

Object-oriented design in C language

Time to reduce my drafts messages here. This topic is going to be bond to the object-oriented approach used in C.

Object-oriented design patterns in the kernel, part 1 []
First part of this series is focused on vtable in kernel, NULL pointers as function pointers.

Object-oriented design patterns in the kernel, part 2 []

Inheritance and polymorphism in C []