At Halloween our home automation system has a few additional and changed
behaviors. Here are some of them ...
1. When a visiting car comes down the drive the usual alert in the
house is replaced with a spooky noise. (Normally the driveway alarm is
the gentle tweeting of birds -- something that could easily be mistaken
for an ambient noise if you didn't live here and know what it means.)
2. When you approach the front door there's an alarming shuffling and
scratching sound from the bushes in front of the garage.
3. When you open the front door to visitors it plays another Halloween
clip "Hello Children ... " in a spooky voice.
4. The media player automatically allows any Halloween-appropriate
songs to play when on random play. Normally such songs are skipped
automatically. So you just might hear the Monster Mash, for example,
mixed into the normal random rotation.
I've been working on home automation for over 15 years and I'm close to achieving my goal which is a house that understands where everyone is at all times, can predict where you are going next and can control lighting, heating and other systems without you having to do or say anything. That's a true "smart home".
An overview of the many sensors I've experimented with for home automation including my favorite under-floor strain gauge, through all the usual PIR, beam and contact sensors to some more esoteric devices like an 8x8 thermal camera.
One way to reduce the volume of sensor data is to remove redundant points. In a system with timestamped data recorded on an irregular interval we can achieve this by removing co-linear points.
Home automation systems need to respond to events in the real world. Sometimes it's an analog value, sometimes it's binary, rarely is it clean and not susceptible to problems. Let's discuss some of the ways to convert these inputs into actions.
Another super useful function for handling sensor data and converting to probabilities is the logistic function 1/(1+e^-x). Using this you can easily map values onto a 0.0-1.0 probability range.
In a home automation system we often want to convert a measurement into a probability. The ATAN curve is one of my favorite curves for this as it's easy to map overything onto a 0.0-1.0 range.
An if-this-then-that style rules machine is insufficient for lighting control. This state machine accomplishes 90% of the correct behavior for a light that is controlled automatically and manually in a home automation system.
