Comments blocked for unregistred users because of SPAM

September 29, 2014

I am having a huge problem with SPAM comments last weeks. Because of that my site was already disabled by my hoster because my database and traffic exceeded the limits. For this reason I have disabled commenting without user account. If you would like to get in contact with me, please use the contact form. Will see how I can solve the problem…

Enable full (Internet) VPN tunneling in Linux Network-Manager

September 12, 2014

I have successfully configured a VPN connection to my home router, thus, I was able to access machines in my private LAN. Moreover, I wanted to tunnel my whole Internet traffic over this connection. Even a google search could not answer, how I could solve this with the network-manager which is used in most Linux desktops.

Finally, I figured it out. You need to go into the configuration of the particular VPN, further into the tab IPv4-Configuration, click on button routes and there you have to remove the tick from box which is probably named in English something like “Use this connection only for resources of current network”. German screenshots are attached below.

Building ROS hydro from source on Ubuntu 13.10 Saucy Salamander

February 25, 2014

This post will cover the steps I made to build ROS hydro successfully from source on my Ubuntu 13.10 amd64 with German localization settings.

1. Add repositories

http://wiki.ros.org/hydro/Installation/Ubuntu

sudo sh -c
'echo "deb http://packages.ros.org/ros/ubuntu raring main" >
/etc/apt/sources.list.d/ros-latest.list'


wget http://packages.ros.org/ros.key -O - | sudo apt-key add -

sudo apt-get update

2. The basic building procedure is covered in the article below, but I will list all commands/steps I have used from this tutorial as well, together with links to resources which helped me solving problems and how I solved them. If you want to have an explanation of the steps, please refer to the provided links.

http://wiki.ros.org/hydro/Installation/Source

sudo apt-get install python-rosdep python-rosinstall-generator
python-wstool python-rosinstall build-essential

sudo rosdep init
rosdep update

mkdir ~/ros_catkin_ws
cd ~/ros_catkin_ws

rosinstall_generator desktop --rosdistro hydro --deps --wet-only
--tar > hydro-desktop-wet.rosinstall

wstool init -j8 src hydro-desktop-wet.rosinstall

rosdep install --from-paths src --ignore-src --rosdistro hydro -y

3. In order to prevent language problems on a non English system, I used following hint.

http://answers.ros.org/question/124081/unicodeencodeerror-while-installing-ros-on-debian/

export LANG=en_US.UTF-8

4. Resolving another build error:

http://answers.ros.org/question/114386/ros-hydro-from-source-on-ubuntu-1310-make-error-in-qt_gui_cpp/

sudo apt-get purge libshiboken-dev shiboken

5. Finish the build process and install ROS to a custom location.

sudo src/catkin/bin/catkin_make_isolated --install

--force-cmake
--install-space /opt/ros/hydro_custom

6. This command needs to be run every time before you are using ROS. For simplification just add it to your .bashrc

Truecrypt performance test on Netgear ReadyNAS 102

January 1, 2014

Happy New Year everybody!

This follow up post to my last article about using Truecrypt on my ReadyNAS 102 (with  two Seagate Pipeline HD ST2000VM003 – 2 TB – 5900 rpm RAID 1) (http://www.ceh-photo.de/blog/?p=809 ) will examine the transfer performance while using Truecrypt.

Test setup:

For comparison I have tested as well on my desktop PC:

  • Intel Core i3 2,98GHZ (Clarkdale)
  • 12GB RAM
  • WD Blue 1TB hard disk

My computer and the NAS are connected by a 100mbit Router only, unfortunately not by Gigabit-Ethernet. If someone could provide some test results using a 1Gbit router, I would be glad to get them.

The test container had a size of  2GB formatted with FAT32 and I used the default encryption settings with AES and RIPEMD-160 hashing. The test script first wrote 1GB of random data and read it afterwards.

See the test script below:

Truecrypt on Netgear ReadyNAS 100 series (Debian) with auto mount on attached keyfile thumb drive dongle

December 30, 2013

Since I own a Netgear ReadyNAS 102 I was wondering how I could use encryption for special content in a convenient way. Because the Netgear firmware does not provide an encryption feature inside its ReadyNAS OS wrapper on top of the underlying Debian Linux I decided to have a closer look on Truecrypt, which I already have in use on my other desktop and mobile computers.

Because Truecrypt binaries are not available for the used ARM architecture the first required step was building Truecrypt from source. During my research I came over a posting which explained the build process step by step.

http://www.readynas.com/forum/viewtopic.php?f=11&t=63214

If you really want to build it on your own, be aware of my comment inside the forum thread above. If you just want to go ahead, I have simplified the procedure for you with a prebuild binary available on my personal Debian-Dropbox-Repository:

Adjust exif timestamp on command-line with exiftool

November 30, 2013

I just realized that I forgot to change the timezone/time settings in my camera since I am back from Asia (~6month). In order to fix the timestamp on all my photos I made during this time period I used exiftool for doing this on the command-line.

Move all timestamps minus 6 hours for all picture files (JPG and RAW) in current directory.

exiftool -AllDates-=6 .

Check if everything is like expected and delete the backup copies in current directory:

exiftool -delete_original .

Because I am working with Corel AfterShot (former Bibble) I had another problem. AfterShot is dumping the timestamps for all adjusted files into the xmp file and is also using these timestamps as first choice for displaying inside the application. But I figured out, that this information in not required and I just deleted it from the xmp file with sed.

Delete timestamp lines from mentioned files for all xmp files in current directory:

sed -i -E '/.*bopt:Date|DigitizedDateTime*/d' *.xmp

Actually a simple operation, but maybe helpful for someone else.

First Robotics Hackathon in Malaysia

April 30, 2013

It was a very, very awesome experience, even it was stressful for me to manage to give all the help the people needed.

But read more here:

http://news.mylaunchpad.com.my/lifestyle-entertainment/article/articleid/240547/youths-build-robots-to-protect-malaysian-shores

http://www.digitalnewsasia.com/digital-economy/makeweekend-kicks-off-2013-with-robotics-theme

I am proud to were part of this!

Android-x86 for Acer 1825 and others development terminated

April 30, 2013

Many of you guys have maybe already thought, that I will not continue the Android-x86 development for the Acer 1825 and all the other laptops I was supporting as well in the mean time, because there was a long time without any updates. But actually the reason was, that since I am in Malaysia I had not much time to work on this and much more I did not have a proper machine for building. So my plan was to continue the development once I am back at home in Germany, what is actually very soon.

But fortune was taking another way, so sad for me and also for all of you guys who used my build all over the world, my poor, poor Acer was snatched from me while I was working in a Park me around a week ago. This is not only sad, because I lost my nice hardware, even so I lost data…..So very disappointing for me….  I am very sorry, but now I do not own a x86 touch device anymore and that is the reason why I will now finally terminate my Android-x86 efforts…even I had other plans…