What is Home Automation?

Home Automation involves using a computer to control various systems around the house, based on logic, rules and inputs received from sensors.

The controlled ‘systems’ typically include lighting, heating, security and music. Sensors are mainly temperature sensors and motion detectors but there are also a couple of network-attached cameras: the system can be instructed to do certain things when it detects movement on one of the cameras.

No, not our house (no pool yet) - but you get the idea
There are also various programmable switches and buttons around the house which can be used to instruct the system to carry out specified actions. The whole thing - lights, heating, music - can also be controlled from an intelligent device such as a smartphone, not just in the house but anywhere you have an internet connection.

No thanks
The system has the ability to be voice controlled from anywhere in the house but this would require open microphones around the house which isn’t very practical. And we’re both too shy to dress up as Captain Kirk so that we can shout commands at a computer.

Communication between the computer and the various sensors and systems is mostly wireless (433 MHz) but some devices are communicated with via ethernet (cat 6 cable or Wi-Fi) or X10, a home automation protocol which uses the mains wiring in the house to communicate between attached devices.

The system has a built-in webserver so we can log in to it from a computer or smartphone anywhere in the world. We can check the status of any of the connected devices as well as instructing the system to carry out actions. We can also check out any of the attached cameras.

The system needs to be on 24-7 and is best run on a dedicated computer but it doesn't need to be a powerful one. Ours is currently running on an old Samsung laptop with a Centrino processor at 1.8 GHz.

A Day in the Life of  a Smart Home

The day begins with music playing on the Squeezebox in the bedroom. Over a period of 10 minutes the volume is slowly increased so that waking up is as gentle as possible.

When it’s time to get up, we press a button next to the bed which sends a message to the computer to carry out a series of actions. First, the lights throughout the house are switched on. Next the music is muted. The local weather forecast (taken from the BBC website) is then announced, following which the music is un-muted. Depending on the actual weather outside, helpful advice might be added to the announcement. For example, if the temperature is below 3°C outside we hear ‘Take care, it might be icy outside’. Or if the UV index is high we are advised to apply sunscreen. This doesn't happen very often.

Between waking up and leaving the house the time is announced at 15 minute intervals so that we don’t have to keep watching the clock as we wash and dress.

The system can be controlled around the house
The system is constantly monitoring the motion detectors around the house and if it detects no movement anywhere in the house for 15 minutes it assumes that the house is empty. All lights are extinguished, the music is switched off and the heating thermostats are turned down.

If someone enters the house while we’re away - generally something we’re not keen on - they are spotted by one of the motion sensors and the system silently sends us an email message. If we’re not expecting anyone we can decide what to do about the intruder. Using a smart phone I can log on to have a look at them through one of the cameras.

If we’re not home when it starts to get dark, the lights will be switched on so that we don’t come home to a dark house. The outside light is also switched on so we can find our door keys in the dark. During the lighter months the lights stay off until we get home - as we walk in the front door a motion sensor spots us and tells the computer to switch on the lights. As we arrive the music in each room is also switched on.

If we get home very late, the house lights might have been switched off (simulating ‘bed-time’) but the outside light will be left on to guide us home.

If we are away on holiday we set the system to ‘holiday programme’. Until we return home the system will automatically switch the lights on in the morning and off at night. The exact times vary to give the impression that someone is home. It will also switch off the heating, although if it is really cold it switches on some background heat so that the pipes don’t freeze.

Thermometers in each room monitor the temperature and the system switches electric heaters on or off accordingly. Different rooms have different target temperatures - for example, we like to keep the bathroom fairly warm but keep the bedroom cooler, especially at night. In the summer, temperature readings are used to switch cooling systems on and off in the same way.

There are also temperature sensors in the fridge, the freezer and the pantry which are monitored to ensure that the temperature stays within acceptable limits for food storage. The fridge, for example, should be no warmer than 6°C and no colder than 1°C. If the temperature goes outside these ranges for more than a few minutes an audible announcement is made and visual messages appear on the Squeezeboxes. If there is no-one in the house I am sent an email instead. I can then contact a neighbour who can, for example, check if the fridge door has been left open.

G'night John Boy!
At bedtime, we press a switch next to the bed and most of the lights in the house are switched off except some reading lights in the bedroom and a light in the bathroom. The music throughout the house is also switched off except for the music in the bedroom.

When we have finished reading we press another switch and the last remaining lights are switched off. The music stays on quietly in the bedroom but then goes off after 30 minutes by which time we are both fast asleep - and so is the house.

I often get up and walk around in the night. If I go into certain rooms well away from the bedroom, motion sensors detect this and the system switches on some very limited, dimmed lighting. A minute or so after I leave the room and return to bed, the lights go off.

Then the house is just waiting for wake-up time and it all starts again.