HOME AUTOMATION

OR HOW TO MAKE YOUR HOME FEEL SENTIENT

The Spark of Interest

I've been interested in home automation for a while. The concept of an intelligent house, where devices could be controlled remotely, and would be automated for both comfort and energy efficiency was very appealing. I initially followed developments of some aspects of both the future looking developments from places such as BT Labs, and MIT's Media Lab and their Things that think programme and Project Oxygen, and thought that if I wanted the level of home control that some of their futuristic looking projects provided, I'd be slaving over a soldering iron to build things myself.

Two things happened to change this;

Firstly, I was involved professionally in a project to investigate the use of active badges for medical applications - this involved embedded microcontrollers, RF and IR communications, and some rudimentary health sensors. It also allowed concepts such as doors being opened remotely, and device control to be examined.

Secondly, as part of the research for this, I stumbled across home automation and X-10 - I was fascinated by this, and saw that it could offer major benefits within a house, and would save the use of a soldering iron, and hooking up the parallel port for device control, when I could put it to better use for reading inputs from various sensors.

The Plan

The automation and networking then grew out of a desire to set up a lab for testing these applications, and expanding the scope of the business. Because of the growth in home automation and home networking, it seemed to make sense to set the house up as a lab, and become a guinea pig for researching and educating about home automation and home networking. This has proved to be very successful.

The Implementation

The home automation came first, but with rewiring of the house needed (due to it having originally been built in the 1920's), it was an ideal opportunity to install Cat 5 networking cable and sockets throughout the house, as well as a Dallas semiconductor 1-wire network, decent security systems, a video distribution system for viewing throughout the house, and CCTV cameras.

The mains electrical system was re-wired to 16th edition standard by qualified electricians, and they also ensured the CAT 5 cable was run at recommended distances away from the mains cabling, as well as the security cabling. The audio cable and 1-wire network followed later. The plan was to develop the technology to operate in a seemless way. Wherever possible, sensors remain fairly well hidden from view, so the house looks as normal as possible.

The Outcome

The house has become a real proving ground, providing an ideal opportunity to build up skills in networking. The house is now fitted with approximately 100 x CAT 5e network points (between 4-20 network points per room), feeding back to a central 19" cabinet with 2 x 48-way CAT 5e patch panels, a 16-way CAT 5e patch panel and a 24-port 10/100baseT Ethernet switch. The cabling is shielded twisted pair CAT 5e cable.

The combination of X-10 units, the home network, video distribution cabling, audio distribution cabling, security systems and the 1-wire network has not proved to be financially crippling. As with any large technical project, the key is careful planning before starting construction work. The result has been very positive. Personally, I am amazed when I see what passes as home automation and "houses of the future" with some of the big house construction companies and other companies - if they class a couple of CAT 5 network sockets per room as making a house smart, then goodness knows what my house must be (and I'd be the first to admit I am hardly at the cutting edge).

The Hardware

In terms of 19" PC hardware, I built 2 old laptops into 1U rack units (the rack units were bought from Maplin), with one initially being used as a Firewall, and the other being used as a home automation server.

The home automation server rack unit is connected via its RS-232 serial port to a CM-12U X-10 interface to drive the X-10 home automation modules around the house.

The rack has since acquired another home automation server sat on top (as well as a few other servers) and another CM-12U X-10 interface, so both Linux and Windows home automation servers can be used.

X-10

The X-10 home automation side of the house has grown over time, so now a large number of household appliances and lights are X-10 enabled (via AM10U and LM10U X-10 modules). The 2 previously mentioned CM-12U X-10 modules handle communications with a Linux PC and a Windows PC, and then 2 TM-12U modules are used for remote control.

Background

A lot of my professional work involves developing Internet and Intranet sites using Perl/CGI or ASP (yes, I can switch between UNIX/Linux and Microsoft platforms), so with regards to home automation, I am generally more active on the software side than hardware side. I've been in the IT industry for 13 years or so, after being in the space science field previously, and have been involved in web related technologies for all the time I have been in IT, so it makes sense to work on what I have experience of. Having said that, I've also got a decent grounding in electronics, thanks to quite an applied Physics degree, so I do enjoy working on the hardware side of home automation too.

Regarding software, on the Perl side, I have generally worked on home automation code making use of Misterhouse, the X10 daemons and the serial Perl module (downloadable from CPAN at http://www.cpan.org/).

On the Windows side, initially I started using ActiveHome, but now I use ACE, since ACE allows code to be written for it.

System Summary

X-10, Linux, Windows 2000, ACE, Misterhouse, iButtons