[Arpad] has spent quite a bit of time reverse-engineering a home automation system, and, as he is quick to point out, presents the information learned for informational purposes only. He’s really done his homework (and documented it well), looking into the US patent application, and figuring out how the protocol works.

If you’re wondering how someone is able to send a signal over an AC sine wave, at least one technique is the proprietary [Universal Powerline Bus]. This works by sending precisely times pulses in conjunction with the wave that would exist normally. Given the correct software on the other end, this can then be decoded and used for whatever data transfer is necessary.

Although as engineers and technologists, we certainly don’t condone stealing patents,  part of point of one is that others are allowed to learn your secrets in exchange for some legal protection. [Arpad]‘s motivation in doing this is that the technology is only widely available in the US with our puny 120 VAC 60Hz power. With this knowledge, he’s been able to transfer it to work with European 230 VAC 50Hz.

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X10 has been around for a long time. It’s the brand name for a set of wireless modules used to switch electrical devices in the home. There’s all kinds of different units (bulb sockets, electrical outlets and plug pass-throughs, etc.) and they’re mass-produced which makes them really inexpensive. Whether you already have some X10 controlled devices or just plan to add them later, we think you’ll find [Jeff Ledger's] post on controlling the system with a Propeller chip interesting. The technique is not Propeller specific and will be simple to port to your microcontroller of choice.

[Jeff] got his hands on an X10 Firecracker. This provides a DB-9 serial connection meant to be used for computer control. But the interface is so simple all you need is two I/O pins feeding the level converter circuit seen above. You can get the TC4427 for less than a dollar, and the Firecrcker module for as little as $6. Since [Jeff] has already covered adding Ethernet via a ENC28J60 he goes on to detail a web-server that lets him switch his devices, all served from the Propeller chip.

Here’s a different ENC28J60 Ethernet tutorial for those interested in webpages from microcontrollers. And then there’s also a ZigBee home automation project if you’re not warming up to the idea of using X10 modules.

[Pete] has an iPhone 4s and loves Siri, but he wishes she had some more baked-in capabilities. While the application is technically still in beta and will likely be updated in the near future, [Pete] wanted more functionality now.

Since Apple isn’t known for their open architecture, he had to get creative. Knowing how Siri’s commands are relayed to Apple thanks to the folks at Applidium, he put together a proxy server that allows him to intercept and work with the data.

The hack is pretty slick, and doesn’t even require a jailbreak. A bit of DNS and SSL trickery is used to direct Siri’s WiFi traffic through his server, which then relays the commands to Apple’s servers for processing. On the return trip, his server interprets the data, looking for custom commands he has defined.

In the video below, he gives a brief overview of the system, then spends some time showing how he can use Siri to control his WiFi enabled thermostat. While the process only works while Siri is connected to his home network via WiFi, it’s still pretty awesome.

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[Scott] wrote in to share a project he is currently working on, a home automation system that relies on Power over Ethernet. While he’s not completely finished, he’s made some great progress, and the work he has done so far definitely piqued our interest.

Part of [Scott’s] design relies on some reverse engineered Blackberry screens we showed you a while back. He has constructed a small control panel for his apartment, which incorporates one of the aforementioned Blackberry screens, along with 10 tactile switches and a PIR sensor. The panel is built to be mounted in a wall or as a standalone unit, allowing him to control various lights and appliances throughout his home.

[Scott] spent a lot of time working on the communications protocol and UI for his control panel. As it sits now, the panel takes advantage of a VNC-like protocol he designed, which allows him to interact with a Java application residing on his desktop computer.

Things are looking awesome so far, and [Scott] already has a handful of improvements planned for the near future. We can’t wait to check it out when it’s finished.

[Julian] wanted a way to remotely control various appliances and lights around his house without spending an arm and a leg on home automation. He also desired the ability to easily switch what items he was controlling without a ton of hassle. Since he couldn’t find anything reasonably priced to do what he desired, he built his own SMS-triggered remote control system.

He designed his system to be used like an extension cord, hence the portable junction box enclosure. This enables him to regulate up to four different items at a time, with the ability to swap out components or relocate his controller at will.

The power strip is controlled by an Arduino which receives commands from his PC via an Xbee module. Any text messages sent to his Gmail account are retrieved by his computer and then transmitted to the Arduino. The Arduino in turn triggers relays as designated by [Julain’s] text messages, utilizing H-bridges to provide the required current.

Check out his schematics and code if you’re interested in implementing something similar in your home.

[Russell] sent in a neat home automation project he’s been working on. Even though the project only has two devices so far, we can already see the potential of his project.

Instead of the X10 standard that has been a staple of home automation for more than 30 years, [Russell] went with ZigBee modules. Aside from being much faster and more flexible than X10 home automation modules, ZigBees also open up a bunch of projects that would be impossible if he went with X10. With some well-placed IR transmitters hidden in his living room, it would be possible to have a TV and cable box controlled via the Internet.

So far, [Russell] built an network-controlled RGB ‘mood lamp’ and an infrared remote for his central air. Everything is controlled through a web app, and [Russell] says that additional modules can be easily added to the code.

Check out [Russell]‘s demo of his project after the break.

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As home automation becomes more and more popular, hackers and security experts alike are turning their attention to these systems, to see just how (in)secure they are.

This week at DefCon, a pair of researchers demonstrated just how vulnerable home automation systems can be. Carrying out their research independently, [Kennedy] and [Rob Simon] came to the same conclusion – that manufacturers of this immature technology have barely spent any time or resources properly securing their wares.

The researchers built tools that focus on the X10 line of home automation products, but they also looked at ZWave, another commonly used protocol for home automation communications. They found that ZWare-based devices encrypted their conversations, but that the initial key exchange was done in the open, allowing any interested 3rd party to intercept the keys and decrypt the communications.

While you might initially assume that attacks are limited to the power lines within a single house, [Kennedy] says that the signals leak well beyond the confines of your home, and that he was able to intercept communications from 15 distinct systems in his neighborhood without leaving his house.

[Aaron Bitler] and [Bud Townsend] have been working a natural user system that is, in their own words, “what android@home should have been.”

The video they posted is pretty impressive. The automation system responds to voice and can control appliances, ‘throw a party’, and provide a user with their location. This is just the foundation of a system that can be built upon - developers  can easily integrate a microphone and speaker into a device so it can connect to the system’s server. Apps, too, are pretty extensible – they’re registered on the server with meta tags that provide a wealth of data to be manipulated. It’s a very, very cool project that we really want to try out.

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