We pulled off a killer demo during the final presentation for people to turn a normal light bulb on and off through their phones.
By Bogdana Rakova (Computer Science Student, University of Sofia “St. Kliment Ohridski)

Everything began last Friday evening when I pitched an idea related to hardware at the local Sofia Startup Weekend event. The first challenge was of course me being a woman, pitching an idea in front of so many people. However, the biggest challenge was talking about a hardware project on an event where people do mostly mobile and web social related applications.

My biggest concern was – can I convey the idea and excite everybody about it in a one minute pitch which is supposed to describe what I’ve been passionate about for more than a year? How do you do this? I assure you that it doesn’t happen the way you imagine it in your head. When I think about it now, I see that Startup Weekend was a great experience, I am glad that I took part and I’m excited about the future possibilities!

What do you think when you see a power socket on the wall? We have them everywhere and they haven’t changed a lot for the past 100 years. Are they that good? Well, meet team Power Home. Our idea is about making power sockets smarter by giving them the ability to talk to the Internet – in a way that we can monitor and control their work. We set out to provide an open source platform that would allow people to visually describe rules between the devices at home and therefore don’t think about everything all the time and be more energy efficient. Wrap this up with an energy social challenge which would allow people to learn from others’ experiences and would turn saving energy into a DIY hacking game where you can do anything you want.

When I learnt that enough people had voted for the Power Home idea on Friday evening, the next challenge was – how should I gather the team? I knew just a few people in the room and as always, everybody is fighting for developers. As time went on, things got pretty desperate – it looked like everybody had found a team already.

What happened then was that I grabbed the microphone and started pointing at a Raspberry Pi I was holding in my hands while shouting that I need developers. The truth is that I don’t even own the Pi – a friend gave it to me two months ago. The Raspberry Pi is very hard to get here (in Sofia, Bulgaria). So during those desperate moments when I was trying to forming my team, the Raspberry Pi drew a crowd of people wanting to have a look!

If I should say just one thing – it is that the team was amazing. I didn’t know anything about the guys I teamed up with on that Friday night. Startup Weekend is a very active and energizing event with a lot of running around, talking to people, work, work, work, and again – running around, talking to people and validating that what you’ve done makes sense for other people too. The magic of the Startup Weekend played its role as we were all focused on the idea and how can it happen.

We set out to build a prototype and prepare a simple demo that would give some practical ideas on what can be possible in Power Home. This was the biggest challenge of all. Open source software and hardware played a key role in bringing the idea forward.

As for the hardware, we used a Raspberry Pi, a light bulb, a relay, a transistor and some resistors and jumper wires. For the software – we used the open source Agilart run time – a web server that we were running on the Pi. It allowed us to send commands and get notifications about occurring events through HTTP requests.

We pulled off a killer demo during the final presentation for people to turn a normal light bulb on and off through their phones. We also demonstrated how you can talk to the Raspberry Pi from a Microsoft Kinect motion sensor.

When you clap your hands, the Kinect device recognizes the gesture and sends a command to the Raspberry Pi over HTTP which would turn the light on or off. The light was connected to the Pi using one of the GPIOs. There are many ways to do it, but you can learn more about how we did it this tutorial.

Working with Raspberry Pi was a great experience and allowed us to get things running very quickly and without much effort!

Kudos to the Power Home team:


From left to right: Bojidar, Kalin, Borislav, Kris, me, Ivan and Kiril. Great job guys!

Here is our demo at Startup Weekend Sofia:

Editor’s note: Got a question for our guest blogger? Leave a message in the comments below.
About the guest blogger: Bogdana Rakova is software developer at Completit, bringing microcontrollers to the everyday people with a Lego-style way of working with real world embedded devices. She was a finalist in the Microsoft Imagine Cup competition for an interactive app teaching people about environmental sustainability. Bogdana’s current project is Graboo, helping you pay attention to nutrition products consumed and how they affect your health. She is currently a computer science student in Sofia, Bulgaria.