One day at TechCrunch Hackathon

Last week on November 14th me along with my colleagues went to attend first ever hackathon by TechCrunch in India. It was sponsored by many companies. The main focus was on their conference. As part of the conference, they conducted a 24 hour hackathon. The event held at Hotel Taj Vivanta, Bangalore.

We didn’t have any idea before going to the event as usual. Just had one idea at the time of the event. The idea was to implement a bidding platform for photos.

And we were able to complete the full prototype for an initial version. I am happy to say that. I have implemented this along with my colleague Phaneendra where I worked on the complete client side and he worked on the complete server side API parts.

We have started with having a simple login system. Since we had limited time, we have used the Android device id as the user login. When the app is installed the unique device id will be sent to the server and it will be used as the main key to identify a unique user.

Instead of having a simple photo bidding platform, it will be good if we can have an option to edit and post the photos. I had worked on adding image filters previously. So it was quick to integrate it within this app. So we have added a feature to edit the photo taken from camera or from your SD card. In the mean time, he created an api for uploading pictures from client device. The api was integrated from the client side.

Till now, basic image editing app setup was done. Then we created the bidding platform. He created an api so that it will list all the photo links through an api. I have integrated it with the app so that it will list all the photos so that user can bid for a photo.

We have set our own bidding logic. Any user can upload their photo. It is voluntary, not mandatory. So that other user can bid on the photos they like. When a user upload a photo, they can set a bidding base price. Other users can bid only on an amount bigger than the base price. Each photo will go on 1 week time for bidding, at the end of one week the highest amount bidding user will be notified and the photo will be given to that person and also it will be deleted permanently from the server. And we have a limit of 20 biddings per day on a photo.

Apart from this we show exif data(meta data) from a photo. And also user can like a photo and also they can set the photo as their wallpaper.

Future plans on this:

1. Integrating payment option
2. Integrating photo printing service directly from the client
3. Integrating OpenGL based Image processing for faster image filtering
4. Integrating AWS on server(We have for 100$ credits at the event from Amazon)

We have used one of my server as the back end. Here is some sample API that we have used:

Here is our final product:


Frequent WLAN disconnection in Ubuntu 12.04

I am getting random frequent Internet disconnection in Ubuntu 12.04. I don’t want to upgrade it. Since it is LTS version and also I have a lot of PPA packages installed. I don’t want to disturb the current development environment. I got a solution from

karthi@spark:~$ lsb_release -d
Description: Ubuntu 12.04.2 LTS
karthi@spark:~$ uname -mr
3.2.0-40-generic x86_64

Restarting network…


RabbitMQ server setup with Android app communication

I spent more than 12 hours in setting up RabbitMQ server in Ubuntu and creating an Android app which communicates from server and also communicates with other devices through the server. So I thought it will be good to share the whole information I found in a single place. I found information from various sources.

And as usual from

I am using Ubuntu 12.04. This tutorial is completely based on this. So I am not sure how will it work on Windows or Mac OS.

A. Install the latest version of RabbitMQ as per the instruction from here

  1. Add the following line to your /etc/apt/sources.list:
    deb testing main

Connecting Kindle Fire and Kindle Fire HD in USB Debugging mode

I am working on Android application development for mobiles and tablets. I faced issue in connecting Kindle fire and Kindle Fire HD in USB debugging mode in my Linux machine to work with Eclipse IDE. Both are not in same way.

Connecting Kindle Fire in USB debugging mode in Linux

1. Connect the device with the system using USB

2. Type lsusb in terminal and check whether you are able to identify the device as “Lab126”

3. Open etc/udev/rules.d/51-android.rules file

sudo gedit etc/udev/rules.d/51-android.rules

4. Paste the following line in the file

SUBSYSTEM==”usb”, ATTR{idVendor}==”1949″, MODE=”0666″, GROUP=”plugdev”

5. Chmod of the rules file

chmod a+r /etc/udev/rules.d/51-android.rules

6. Open home/username/.android/adb_usb.ini file in edit mode. Add the following lines in the file manually. Don’t copy and paste. You will get issues on spaces.


7. Run adb kill-server

8. Run adb start-server

9. adb devices


Connecting Kindle Fire HD in USB debugging mode in Linux

This is simple.

Go to Settings-> Click more settings in top right ->Security ->Enable ADB.

That’s it!



Copying contacts from Nokia Symbian mobile to Android mobile

Finally, I moved to Android mobile. I faced issue in importing all the contacts from Nokia mobile to Android. I tried with Nokia OVI suite and PC Suite. Both allows me to export every single contacts in a .vcf file. You can import that file into Android contacts easily. But the problem was I had around more than 1000 contacts in my mobile. It is not an easy work to import each contact separately. There is an easy way to overcome that.

Export all the contacts into separate .vcf files. And then compress all the contacts into single .vcf file and import. The option /B is to mention that it is binary file. That’s it.

copy /B *.vcf all_contacts.vcf

Now send the file through usb or mail to your mobile and import into your contacts.



from Microsoft Windows 8 AppFest contest

Attending Microsoft windows 8 AppFest contest today at Bangalore. The reason why I got more interest towards is they are planning to set a world record by gathering more developers at a place for coding. It is a continuous 18 hours coding contest. I am done with three apps. I have got a free access to MS Windows 8 App store. Feeling good. Because the program night was not wasted. Still there is 2 more hours to go to set Guinness Record. I will get that certificate also 🙂

I love technology. Currently I am working on developing Apps for Android tablets which is being completely developed in Linux platform.