Code and programming

All posts, articles, pages that have anything coding and programming related. For sections or a finer selection, navigate to sub-categories.

How to embed script in wordpress footer

Another “tip of the day”. I ran into this while testing some carousels and swiping banners. All needed the associated js scripts to be loaded lastly after the main page/ post content was already available. It seems that using wp_enqueue_script last argument as true will do the trick: Hope you will find this useful. Cheers […]

Why CSS margins collapse

While working on my new theme for this site I ran into a problem: CSS collapsing margins. Well, from the beginning let me be very clear: this will not be a comprehensive article on this subject. There is already one written by Josh Comeau and is excellent: “The Rules of Margin Collapse“. I urge you […]

Genetic algorithm mutation coded in Python

This example is adapted from Clinton Sheppard’s excellent book “Genetic Algorithms with Python“, a book that I encourage you to buy and read. The very simple example shows how easy is to design in Python a simple mutation algorithm that merges to the optimal solution in 24 iterations. The example below uses romanian language accents […]

How to install Python 3.7 on Raspberry Pi

This short guide explains how to install Python version 3.7.0 on a Raspberry Pi running Raspbian. First, get rid of old versions: Ensure system is up to date: Install the dependencies needed for building the distribution: build-essential tk-dev libncurses5-dev libncursesw5-dev libreadline6-dev libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev libffi-dev Get the python src distribution: […]

Abandoned Posts

Over the past seven years (the age of this blog) I started writing several articles that I never  finished. It’s time to trash them completely or just add them to a list for future afterthoughts. Who knows ? So, from older to newer: “Weller WD 1000 M Review – Part III – Software”, January 18, 2013 — […]

More about zombies and XCode

Some time ago I did a very short introduction about enabling zombies when debugging in XCode. As a refresher, zombies is a Cocoa feature that turns any object going to be deallocated into a NSZombie instance. This will not prevent your application from crashing, but instead of getting a stack dump from Xcode that is a […]

XCode 5 LLDB Debug Assertions

One situation when a debugger might not be the first option is when you are not sure where does a program has a bug. One way you can check whether your assumptions are truly what is happening in your code is by using assertions. What assertions let you do is express one particular assumption and […]

SCPI on Mac

Some more days passed and some more finishing touches added to my MacSCPI app. It is entirely dependent on hooking the device via the USBTMC driver, but it works fine and is stable: I had some problems with buffer padding and the output it is still not 100% gibberish–free , but I assume I have to play with […]

USBTMC driver for Mac

After some head banging, I finally managed to send SCPI commands from my Mac to my Agilent (Keysight) DSOX2002A. I’ve worked on this since december last year. Almost a year, but I did not spent a sustained amount of effort. I did it just during my free time. I still have a day job that […]

Writing serial drivers for OS X (1)

At least one thing can be improved on Mac Dev Center: the code sample repository. I am not talking about documentation. In this particular case, there’s not much new to write about. The I/O Kit documentation (grab the pdf while it is stil there) is sufficient. On the shelves are tons on books about C and […]


The keyword __attribute__ allows you to specify special attributes of struct and union types when you define such types. This is mostly encountered when designing code with particular care on memory footprint optimisation.  I have encountered this several times in some Apple headers while digging for documentation for my kext projects, and I thought it […]

IOUserClient and IOExternalMethod

While developing the OS X driver for my Agilent DSO-X 2002A oscilloscope, I ran into a topic that I found to be poorly documented. It is about interaction with a device driver. There are several ways to communicate with a device driver from client space (the application). One is by modifying driver properties. This method requires […]

Agilent DSOX 2002A

Agilent DSO-X 2002A driver for Mac OS X

December again, another year passed. Traditionally, this is a month when I am taking a long break. But I was up to something in the past days and I wanted to share. I have created a driver for my KeysightAgilent DSO-X 2002A oscilloscope. Maybe not a big deal, but huge for me because this is […]

Writing a (working) USB driver for OS X

For some time I was struggling with an ambitious project, to write a Mac driver for my Agilent DSO-X 2002A oscilloscope (see here). The reason behind this is SCPI and the opportunity to reach fresh perspectives in computer–measurement instruments’ integration. However, it was not an easy way. More of a reverse–engineering project, was very time–consuming […]

Missing WordPress Link Manager

WordPress users that updated the blog platform to version 3.5 might have observed that the link manager is missing from the admin pages: It seems that WordPress announced this as one of the major core changes when they released version 3.5: One other major change is the Link Manager. If you’re using it, you’ll want […]

Changing FTDI descriptors

I was struggling for some time to make my Mac communicate by USB with Arduino. It is part of a larger project of an USB-controlled Lab PSU that I am currently in prototype stage. Part of these problems solved when I finally realized that you cannot use an Arduino as an USB controller simply because […]

Using arrays of checkboxes to store and retrieve WordPress options

I am into a complex task: for some time I’ve wanted to update the theme of this site and make it more versatile. Despite my obvious lack of time, the content is increasing steadily, so is the number of visitors, and I feel more and more often the need to structure better all these posts […]

Simple and default UIPickerView

UIPickerView Tutorial — part 2

Before we continue the second installment in the series of basic tutorials about UIPickerView usage and customization, a short digression. Most Cocoa/ Cocoa Touch tutorials assume that all connections to delegates, data sources and outlets are done visually in XCode. Our previous example was no exception. You can see from the project (gave the link below) […]

Usage of void in C

Going into some USB programming for a project I am into (on my Mac), I ran into this and I thought would be nice and useful to elaborate a bit. This is about void* pointers and callbacks in C. USB device discovery and probing under IOKit makes heavy use of callbacks, I wanted to write […]

Using LLDB Commands in XCode 4

The rationale for Apple’s move to LLVM and slowly parting with the aging GCC has a long history and is out of the scope of this brief tutorial on LLVM commands. The primary reason for switching from GCC to Clang — probably — is the incompatibility of GCC’s GPL v3 license with the goals of […]

AVRISP mkII unboxing


Until recently I have extensively used my MacBook, AVRDude and USBTiny for my μController projects: Now I got myself a proper tool, the AVRISP markII, mostly because I wanted to use AVRStudio 6.0 features: Key features: Programs both flash and EEPROM Supports fuses and lock bit programming Upgradeable for future device support Supports target voltages from […]

Webpage design thumb

Redesigning the blog

I decided a need a new theme for this blog. Rolled my sleeves and started to work.

How to create Arduino brush for Syntax Highlighter

For my Arduino lessons I needed to add WordPress support for Arduino syntax highlighting. A custom brush for SyntaxHighlighter plugin that would format and color my Arduino syntax similar to the application (see here an example). This is what I did.

Code for Weather Station prototype

I took some steps in learning the capabilities of Arduino Platforms. Below is the code of my Bluetooth-enabled temperature reader with OS X integration.