Wednesday, September 24, 2014

No enough space in /boot partition in Ubuntu 12.04 64bit

This morning I faced a trouble when I turned my Ubuntu 12.04 computer on. Update manager showed up with some updates however  when I go ahead to install them, it says I don't have enough space in my /boot partition. After getting crazy for a while and searching in google, I found that I should either resize my /boot partition to provide enough space or remove some unnecessary stuff from the existing /boot partition. Since the stuff in that partition are critical things such as older kernel, I was afraid about removing them. I thought the best solution would be resizing the partition but for that I need to boot the computer with a Ubuntu live CD.

Fortunately or unfortunately, I couldn't find  a Ubuntu CD for this purpose at that moment. Therefore, I left my fear behind and decided to try the /boot clearing option. I issued following long command in the terminal which ran for a while printing various outputs and finally ended. At the end, I installed the updates and it worked fine thankfully. The good open source community saved my life :)

The command to remove older kernal files from /boot partition.

sudo apt-get remove --purge $(dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d')




Saturday, September 20, 2014

A visit to CGR workshop at Rathmalana

Few weeks ago, I got a chance to visit Rathmalana railway workshop. This is where almost all the railway engines and other equipment are repaired. This workshop is dispersed over so many acres of land with different factory buildings. I went their with Dr. Kasun and few other members of the lab. In this journey, we were lucky to get into a Class S9 locomotive engine. Following are few highlights from the journey.

A factory building inside the workshop which repair railway engines.

Inside the factory.

An engine frame completely rebuilding. Perhaps it's got destroyed from an accident.

The Class S9 engine to which I got into.

Drivers view from inside the Class S9 engine.
This is something unforgettable and a rare chance. Therefore I think I will never forget about this visit.

Thursday, September 11, 2014

The lack of good pdf editor availability for linux

While having so many good free software for Linux, still I run into trouble when I have to edit some PDF document such as filling a form provided as a PDF. Due to the unavailability of a good PDF editor, I had to use an on-line PDF editor called PDFescape in this morning to fill a form. It was the first search result I got from a Google search and it did the job well. Since it is a free tool, I paid some gratitude by clicking on some advertisements.

It seems more on-line PDF editors available which I didn't try yet. However, when next time I run into trouble with editing PDF documents, I should not forget this on-line tool I discovered this morning.

Sunday, September 7, 2014

Eclipse crash while exporting APK with Android ADT plugin

When I try to export an Android app as an APK, eclipse suddenly crashes without any clear error message.  I experienced this issue with Android ADT plug-in in Eclipse sometime back and found the solution that time. Today, with a new version of the Android ADT plug-in, I faced the same issue and took a long time to find the solution by googling. It was my mistake that I didn't write down the solution in the first time. Today, I'm doing it. The solution was so simple. We have to disable automatic building functionality of Eclipse before we export the APK. 

From the menu bar in Eclipse, goto Project->[]Build Automatically and remove the tick. Now we can proceed to export the APK without any issue. After exporting, I can put the tick again.

Saturday, September 6, 2014

Brainstorming with LEGO mindstorms

Recently a fleet of LEGO mindstorm EV3 kits arrived to our lab. They are supposed to serve as some learning aid for the students who are studying Cognitive Robotics course. From the first day of the reception of these kits, I was waiting for a free time to put my hands on them. Finally, I spared some time for it. Among different sample robot designs, the one which took my attention and also the easiest one to build was TRACK3R robot since it looked like a mars rover to me.

One thing I realized while playing with the the LEGO kit is, there is a huge impact on our creativity while we are interacting with physical objects and models rather than brainstorming only with the mind. While assembling the components of the TRACK3R robot, so many beautiful ideas came into my mind about different things we can do with small robotic vehicles. Some people thinks that working with the LEGO kit is kids stuff and expressed such comments while I was working with the LEGO kit. However, I know the value of this. Therefore I don't bother about the time I spend on playing with LEGO kits.

After putting the batteries and powering up the control brick of the LEGO robot, I found a familiar friend inside it. This brick runs a version of Linux kernel. Well, that's a good news.