(#4) You Don't Need a Weatherman
There's another hunk of hardware in my house that contributes to the Slightly-Less-Dumb-House ecosystem: a weather station.

According to my unscientific, unpublished studies, most nerds exhibit an affinity for music and an interest in weather.

To feed that interest, yet acknowledge that there's little real value in the endeavor, I bought an weather station for about $90 USD.


LaCrosse - A Game, A City and

The maker of my inexpensive and accuracy impaired weather station is LaCrosse Technology. I picked the WS-2308 AL model for a handful of reasons.  First it was cheap, and second it came with the ability to communicate with a computer.

Open Source to the Rescue
The communication protocol between the weather station and the computer is closed and proprietary.  I think LaCrosse will sell you the specifications.  I'm not sure.  I'm sure I don't care.

As with my Eaton Home Heartbeat system, someone's invested the time to reverse engineer the protocol.  They've documented it and even written some software, freely available.

If you're curious, and if you happen to have one of these models (also discontinued) then you're welcome to browse Kenneth Lavrsen's Wiki Pages.


Another Closet, Another Pi and more C
Like the Home Heartbeat System, the weather station is in a closet, connected to another Raspberry Pi and has some of my 'C' code that uses the Open WS2300 protocol to query the weather station about current conditions.

The current conditions are broadcast to the network (more on this later) and find their way to a MySQL database on another server (yes, in a closet, but no - not a Raspberry Pi).

I've had this setup for several years. The weather station predates the Home Heartbeat System and the current conditions are viewable on a simple PHP based webpage.

While semi-interesting, it turns out that the weather station is just another set of sensors that can contribute to the Home Automation ecosystem.

Is there anybody out there?

I don't want to jump too far ahead, but a common use case I'm bumping into, with Home Automation, is trying to infer when the house is empty.  Sure -- plaster motion sensors everywhere. Toss in a lot of creepy cameras.  That would do it. But it would be creepy.

But take a look at this graph. This is from the weather station's indoor sensors. It shows the interior temperature and humidity:

Do you see that humidity spike about 6:30am?  That's me jumping in the shower. (Well, not literally jumping up and down while inside the shower.  I'm using an idiom. It means I've started the hot water running.)

And we've found another way of inferring that someone is home.

If we see a second floor, interior, humidity spike, between the hours of 6 and 7 am, Monday through Friday, then someone's home.  Me.

Interesting.

I didn't expect that.

Based on this event "a sudden rise in the humidity from the sensor on the second floor" we can assume the house is occupied.

We take the output of one event and make an assumption.

Come to think of it - I have another sensor, on the first floor, that measures temperature and humidity too.