Smart Home - Lacking standards and lock-in
paul at fsfe.org
Thu Dec 18 14:26:54 UTC 2014
Nico Rikken <nico.rikken at fsfe.org>, Tue 2014-12-16 09:20:
> I'm curious how you conceive the developments in this field, in your
> country and for your use-case.
My personal perception (Berlin, Germany):
- home automation is not wide spread, but there are lot's of offers in
electronic stores and it's probably coming
- there are different vendors with some systems beeing compatible to
- almost all (or rather all) products are radio based, signaling via
modulation on the power line, or at least an extra wire seems not yet
to be state of the art
- Higher priced vendors offer "Cloud"-Controlled systems exclusively,
the radio signal is encrypted (similar to remote car keys)
- Products from cheap vendors are quite hackable and there is a
healthy community growing around their products
- However unencrypted radio in cheap products and a limited set of data
codes means, your neighbours remote will switch your fridge
My opinion is, that lacking standards are not so much the issue, mostly
because the technology is so simple that a lack of documentation doesn't
so much become an issue yet. Of course that hasn't have to stay true in
For me the probem is rather the control architecture of the high end
systems. After buying a product users stay dependent on the company's
internet servers to talk to their devices and those servers are always
in the control flow, being technically able to switch devices and to
record the user behaviour. This makes me thing of the teweets cited by
This is not stricly a Free Software issue, but has more to do with
consumer rights, security, privacy, and even more with
== My personal tale: ==
Requirement: switch my audio amplifier on and off from the
RasPi/NanaPi/Homeserver, preferably automatically whenever I launch
Idea: run some ip packet over the existing ethernet in my home to switch
some kind of smart wall socket/ junction box. How hard can it be?
Those kind of ethernet junction bars have been around since the
nineties. They run a primitive HTTP-Server and you can switch individual
sockets by calling the right URL on the server. Simple, cool, failsave.
Problem: they somehow failed to get any cheaper ever since the nineties.
Prices are between 100 and 200 Euro for a single 6-Socket bar.
There is also a wireless LAN version with a single socket for around 40
Looking for home automation systems:
More expensive systems come with a control station and comparatively
dumb electronics in the power switches. Starter sets cost between 50 and
200 Euro, including a control station and a hand full of wall sockets,
light switches, junction boxes, dimmers, etc...
All of them advertise easy access via a smartphone. This is what seems
to get a lot of buyers interested while it was getting me very scared.
It would be viable to run a web server on the control box and configure
a port forwarding on your home router, right?
But this wouldn't be as "easy" as in iPhone. To get the advertised
behavious even when behind a NAT gateway it is pretty clear what has to
happen: The controller box connects to an internet gateway run by the
vendor. Joe Normal tells his iPhone to tell a company's gateway server
to tell his smart home to switch on the 4000 Watt heating fan. And he
doesn't even know. The packaging doesn't mention the vendor provided
service in one word!
Can you tell the controller to connect to your own gateway instead? I
contemplated setting up a DNS filter to direct it to my own gateway. But
does the controler check the vendor's VPN certificate before connecting?
(Notice how encryption will work against you in this case!) And even if
the connection works, what protocol will the controller speak? Will I
actually be able to query device states and send switching commands?
It would have been interesting to try. But in order to do that, I would
have had to buy one of the devices. And doing so would have meant giving
money to what I consider to be the wrong people.
The cheaper solution:
Cheap automation systems have the same veriety of end devices as the
expensive ones. There are wall sockets, dimmers, even thermostates etc.
Control devices come in the form of Light switches (which you simply
stick to your wall), door opening sensors, etc. but usually as a remote
control. The signaling frequency is at 433 MHz - that's a popular band
for RC cars and toys. The devices can be programmed to listen to a set
of specific codes. So you can pair different controllers with differnt
devices. You can switch all devices individually as well as in self
determined groups. Transmitters from the modelbuilding shop can be
attached to your computer. There is some Wikis around which list the
signal codes (didn't remember the URLs). There is also tutorials on
reverse engineering the signal codes using a sound card.
All in all nice friendly toys. I finally went with one of those.
The disadvantage is, that there are only a few dozend signal codes for
each system. When my neighbour starts using the same devices I'll have
to talk to him and agree on code groups. I recommend against switching
high powered devices with this signal.
Running the signal over a wire instead would solve this problem, but so
far I didn't dare to open the case of the power socket.
Paul Hänsch █▉ Webmaster, System-Hacker
Jabber: paul at jabber.fsfe.org ▉▉ Free Software Foundation Europe
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