Tag Archives: c

How to use ancient Morse code to solve a modern problem

Posted on October 3, 2017 by

If you own a Raspberry Pi mini computer the following problem may sound familiar to you: You just connected your Rasperry Pi to a network with automatic DHCP. Now you need to find out what IP address has been assigned … Continue reading →

Posted in c, Information Theory, Linux, Raspberry Pi, Uncategorized | Tagged , , , , , , ,

Subroutines, Functions, Methods

Posted on February 17, 2013 by

Most, if not all, programming languages allow you to create subroutines, functions, or methods, all of which follow the same principle. You can think of them as black-boxes that contain source code to perform a specific task. For example, you … Continue reading →

Posted in Programming Essentials, Uncategorized | Tagged , , , , , , ,

Swapping Variables

Posted on October 7, 2012 by

Many algorithms, including the world-famous Euclidean, require to swap the values of two variables. So you probably know the following principle. int x = 8; int y = 123; int tmp = x; x = y; y = tmp; However, … Continue reading →

Posted in Bit-Twiddling, Information Theory, Uncategorized | Tagged , , , ,

Lost in translation (C vs. Assembly Language)

Posted on October 23, 2011 by

In my classes on microcontroller programming I often draw comparisons between C and assembly language. This is to show my students that either programming language has both advantages and disadvantages. While the efficiency of C code predominantly depends on how … Continue reading →

Posted in Programming Essentials, Uncategorized | Tagged , , ,

Pointers and References – Part 3 (Kinky Stuff)

Posted on April 28, 2011 by

Once in a while, I show my students some fancy examples of what you can (but shouldn’t) do with pointers. Most students would be watching the screen with baffled looks on their faces. Those who cannot find any interest in … Continue reading →

Posted in Pointers, Uncategorized | Tagged , , ,

Pointers and References – Part 2 (Intermediate Stuff)

Posted on April 11, 2011 by

This is my second posting on pointers and references. In part 1 you could read about the basic nature of pointers. Now we will have a look on two very common examples of how pointers are being used. 1. Passing … Continue reading →

Posted in Pointers, Programming Essentials, Uncategorized | Tagged , , , | Leave a comment

Pointers and References – Part 1 (Rookie Stuff ;)

Posted on March 17, 2011 by

Pointers are subject of fear for a large number of people. Some of them hate pointers because they can cause nasty problems that are difficult to debug, others hate them because they never really understood what pointers actually are. Indeed, … Continue reading →

Posted in Pointers, Programming Essentials, Uncategorized | Tagged , , ,

Parity

Posted on February 23, 2011 by

Data transfer inevitably threatens data integrity. It does not matter whether you save and restore files on your hard disk or you transmit data over long distances. Bits can always get twisted by interfering electric and electromagnetic fields. TCP/IP uses … Continue reading →

Posted in Bit-Twiddling, Uncategorized | Tagged ,

Masking

Posted on February 19, 2011 by

In this posting I’m going to explain a bit-twiddling technique called masking. It is used to extract (and alter) specific bits in a word of bits, for example a byte. You might be familiar with IP subnet masks in network … Continue reading →

Posted in Bit-Twiddling, Uncategorized | Tagged , , , ,