Friday, December 14, 2012

Memories of ICTer 2012 Conference

Title slide of my presentation
Yesterday I attended to ICTer 2012 conference since one of the papers I co-authored is in the proceedings of the conference. Our paper title was TikiriPower – Using TikiriDB abstraction on Smart Home systems. This research was done by the SCoRe research group some time back. First author of the paper was Mr. Lakmal Weerawarne who worked with us for a considerable amount of time. However since now he has left for studying for his Ph.D, I was the person next in the line to conduct the presentation at ICTer 2012.

Our paper was scheduled to be in the Systems and Performance Evaluation session. Prof. Sudhir Dixit from HP labs India was the invited speaker of the session. Even though initially I was a little bit excited since that was the first time I was presenting a paper in this kind of a huge event, after few minutes I gained the confidence to move ahead in the latter part of the presentation. In the Q & A session after my presentation, Prof. Athula Ginige raised some questions but luckily I managed to provide him explanations.

In addition to presenting a paper, there were more benefits of attending the conference. Besides listening to other presentations, I tried my best to talk to other attendees of the conference as much as I could. Among other attendees, three people were so much friendlier to me. Dr. Gordon Hunter had visited with his Ph.D student Mr. Dilaksha Attanayake from Kingston University, London. Both of them were so nice people. Both of them along with few more co-authors had published a paper titled "A Novel Web-Based Tool to Enhance Learning of Mathematical Concepts" in ICTer 2012. So, they were here to present it. Another interesting person I met is  Dr. George Weir from University of Strathclyde, Glasgow. He didn't present any paper but he delivered a keynote speech and conducted an interesting workshop.

Altogether I'm sure the people I met, the experiences and knowledge I gained will leave a footprint in my memory for a long time.


Mr. Dilaksha from Kingston university had taken some pictures at the conference during my presentation. He emailed me the pictures later.

Tuesday, December 11, 2012

Disable kernel messages and getty loggin through UART port in Raspberry Pi

When we are going to use the UART Rx and Tx pins of Raspberry Pi device for some purpose like communicating with an external device, we face a little problem. Linux operating systems send it's kernel messages in boot time to the serial port. Additionally it allows the user to login to the system though a serial console provided though the UART pins. Therefore when we use the UART pins for some other purpose we may get data belongs to the operating system.

After searching the web, the solution I found is to disable this Linux kernel messages coming to the UART port and also the serial console login facility. Here's how I did that.

To disable kernel messages coming to the UART port, open the following file by issuing the command,

sudo nano /boot/cmdline.txt

Edit the content of the file by removing all the parameters which involve ttyAMA0 device. So, the resulting content would look like the following.

dwc_otg.lpm_enable=0 rpitestmode=1 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait

Now save and exit from the nano editor.

To disable the serial console through the UART port, open the following file by issuing the command,

sudo nano /etc/innitab

Find the following line in that file.

T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100

Now add a '#' character in front of that like to comment that out so that it looks as follows.

# T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100

Now save and exit from the nano editor. After editing these two files we are done. When the next time you reboot the Raspberry Pi, you will be able to use the UART port without any disturbance from system level.

Thursday, December 6, 2012

Boot-Repair did the trick !!! :)

In my laptop I had Ubuntu 10.10 for a long time. Recently I wanted to use Ubuntu 12.04 LTS version and therefore I installed it in a separate partition in my machine. So, when I start the machine Grub shows up with the options to select either Ubuntu 10.10 or Ubuntu 12.04 to boot.

However after few days I lost my interest on the new interface in Ubuntu 12.04. Therefore I moved back to use my previously used Ubuntu 10.10 version. Since I didn't need Ubuntu 12.04 installation any further, I formatted that partition where Ubuntu 12.04 is installed. I did that while working on Ubuntu 10.10 version. However when the next time I start my computer I got a prompt which shows 'Grub Rescue>' text.

As I understand, when I format my Ubuntu 12.04 partition the Grub has been damaged. Because of this I couldn't even access my Ubuntu 10.10. At first I thought I would have to do so many configurations to fix this problem. However after searching the web for a while I finally found the solution.

There's a free tool called Boot-Repair which can fix frequent boot issues. This page ( provides all the necessary information to use this tool which has very few steps. So, according to the instructions given I created a live USB stick with an Ubuntu image and then booted the laptop with it. When live Ubuntu USB is booted I went to the 'try ubuntu' option without installing it. After this live Ubuntu desktop is loaded, I installed Boot-Repair tool on this live version. Then I ran the Boot-Repair tool and had to just click a single button. When I restart the machine without using the live USB stick, the Grub showed up providing me the option to go to my ever loving Ubuntu 10.10 version.

That's it. Thanks to Boot-Repair tool I could solve the issue.