Directional Coupler tests

A directional coupler is a device used in radio frequency (RF) circuits and measurement devices. Its effect is quite simple: you can picture an (ideal, 3-port, 20dB) directional coupler as a little grey box with three plugs labeled “IN”, “OUT”, and “COUPLED”. If you feed a RF signal (imagine a 200MHz sine wave) into the IN port, then 99% of that signal will be available at OUT, and 1% be […]

Continue Reading →

Radio Interferometer: status update

As you probably do not know, I’m currently trying to build a semi-digital radio interferometer at 408MHz, for astronomy. I played around a bit with patch antennas, and did some very basic “interferometry” tests with them. Some extremely bad tinfoil patch antennas being used for “interferometry” Basic idea of how this interferometer could work The plan for this telescope goes something like this: There’s an arbitrary number of antennas (the […]

Continue Reading →

usbtmc on newer kernels

Just a quick note, if you want to use usbtmc (tmc is a protocol to control measurement devices remotely), the version in the linux kernel doesn’t really seem to work. There’s one from Agilent which works fine, the installation procedure is described here. However it doesn’t compile on newer kernels unless you do these changes: http://paste.kde.org/625736/ After that, it works just fine:  # cat /dev/usbtmc0 Minor Number Manufacturer Product Serial […]

Continue Reading →

kdev-python 1.4 stable released!

I’m happy to announce the release of the first stable version of kdev-python, version 1.4! As this is the first stable release, this post is supposed to be an overview about what kdev-python actually does. KDevelop with kdev-python 1.4 First of all, kdev-python is a plugin for KDevelop. Its purpose is to make development of python applications more convenient. The main focus of the program is static analysis of source […]

Continue Reading →

Blender: exporting camera tracking markers to CSV

For university, I needed a camera tracker which could track motion of some particles under a microscope, and give me the coordinates of a particle for each frame. Blender has a very nice camera tracker which is ridiculously easy to use (and very fast), but it cannot export its results in a gnuplot-compatible format. But, it has a nice Python API, so you can just do it yourself! This is […]

Continue Reading →

Raspberry Pi i2c and repeated start condition and MAG3110 magnetometer

i2c is a protocol to communicate with microchips. It is widely used if the required data rate is not that high (up to few thousand bytes per second or similar). Reading data from some client (which could be some sort of sensor, or an Analog-Digital-Converter for example) with the Raspberry Pi is usually as easy as just reading from a device file (/dev/i2c-0 for example), specifying the device address beforehand, […]

Continue Reading →

Note about SPI chips behaving in a weird way

In my recent electronics projects, I encountered two cases where a chip supporting the SPI protocol behaved in a weird or inconsistent way when communicating with the computer controlling it. I had an ADS 8320 Analog-Digital-converter (which should measure some voltage 100k times per second in 16bit resolution), which reported data like this when given a monotoneously rising, then falling voltage: Weird data received from an AD converter via SPI […]

Continue Reading →

kdev-python beta 2 released!

I’m happy to announce the immediate availability of the second beta version of kdev-python, the python language plugin for KDevelop! You can download the sources from kde.org; those can be compiled against KDevelop 4.4 (which is the current stable version). Changes over the first beta release include: Two crash bugs fixed Fix a bug in parse priority things (it did sometimes cause documents not to be reparsed after a dependency […]

Continue Reading →

Vienna kdev/kate sprint: kdevelop settings dialog and changes to kdev-python

In an effort to improve the overall quality of KDevelop’s user interface, Aleix and I polished the settings dialog of KDevelop. Since the Kate guys challenged us by showcasing their “awesome” gimp skills, I feel like I have to do that too: Comparison between the old and the new configuration dialog in KDevelop  There wasn’t really any changes to functionality, it’s just supposed to look better and be more understandable. […]

Continue Reading →