ᐅ Open Smart Home System "Prototype for Everyone"

Created on: 27 Aug 2020 10:48
K
knalltüte
Background:

I own an old house (about 270 years old) where my company and my apartment were located. As the office kept expanding with new employees being hired, I moved into a separate apartment due to space constraints.

However, this was not meant to be permanent. I wanted to have something of my own again, but this time “small but nice.”

After considering various options from tiny houses to mini houses, the decision was made to build a small semi-detached house and use one unit myself (about 65m² (700 sq ft) plus terrace and garden).

My brother is building the other semi-detached house, and both units will then be rented out.
High-quality, ecological, and sustainable construction was important to us from the start. A healthy indoor climate, photovoltaic system, heat pump, and controlled residential ventilation were therefore fixed requirements.

At first, I considered some home automation (implemented, for example, with Shelly devices installed later to control certain functions remotely).

But since our company is involved not only in general IT activities but also in software development, programming, and consulting on IT infrastructure and digitalization for larger organizations such as hospitals, and since my brother is the lead developer of a software that has been on the market for over 20 years and is the market leader in Germany in this field…

Couldn’t we do it ourselves?

Yes, we could!

“Coincidentally,” a bachelor thesis on an open (non-proprietary) smart home system was submitted to my brother (who teaches computer science at FOM among other things).

Based on this and other work that proved certain fundamentals, plus freely available information showing many other possibilities of a smart home, we formulated our requirements.

We wanted a “Smart Home” (as we understood it at the time).
We wanted to at least control lighting and blinds, have a front door with motorized lock, possibly video intercom systems, presence monitoring, etc. The wishes naturally grew as we learned what was possible. So, voice control via, for example, Alexa should also be possible (for those who find it useful).

Our key criteria were:
• Open system (no proprietary/cloud dependencies, etc.)
• All active components centralized in the distribution board if possible
• No “bus switches,” but “normal” Gira, Jung, etc. push buttons
• Affordable!
• The base programming can be quite complex (done by experts), but afterwards the system should be adjustable by “non-technical users” via a GUI (This alone could lead to lengthy discussions)
• We will do the wiring and programming ourselves (my brother and one of our partners are software developers, and I am an IT specialist)
• The wiring will be done with plenty of spare capacity and smart home compatibility.
-> Lighting circuits (lamps) all go directly to the distribution board
-> Outlets are wired room-wise to the distribution board and use 5-wire/three-phase cables so nearly any outlet can be switched later with small wiring adjustments.
-> All push buttons are connected with (plenty of) LAN cable directly to the distribution board
(Discussion about CAT7a/CAT8.x LAN cabling or 10DA took place: Result: Almost everything will be done as CAT7A duplex because, overall, it is easier to handle and cheaper for us.)

The result will soon be installed as a prototype in my unit (half a semi-detached house, about 65m² (700 sq ft)). The photo of the small sub-distribution board is only a small part of the test system currently being assembled! The Eltakos were installed only for comparison (space requirements vs. the Controllino) and will probably not be used in the finished system.

Almost anything “speaking” a smart home language can be integrated into the system via the appropriate binding.

The core hardware (the “brain” of the system) will cost about 1000 to 1500 euros (approximately $1100 to $1650). It mainly consists of the SmartHome Manager (Raspberry Pi) and Controllino Mega pure (Arduino).

The programming of OpenHub, etc. (open source) is done by our software developers/programmers.

Temperature, distance meters, motion detectors, humidity, CO2 sensors, and similar devices can easily be integrated. Small touchscreens (around 20€ (about $22)) as “cornerstone components” usually cost only a few euros.

I will be happy to report on further steps and on the prototype development once progress continues.

Notes:

The advantages of KNX are often mentioned, and some of these certainly apply. In our smart home, if the SmartHome Manager (which is also industrial hardware) fails, almost nothing works. With KNX, all unaffected subsystems continue to run. However, the example described by @Mycraft: “… It’s enough to just connect another push button to the bus cable and configure it…” is hardly feasible in practice. The user cannot do it themselves, the proverbial “unicorn” (ideal technician) is not there, and if the “system integrator” does come eventually, every small change or adjustment is extremely expensive. (These are the experiences of two people with KNX in our circle of acquaintances.)

Please do not fill this thread with pros and cons of the various systems. It only concerns “our” system based on the hardware and software components mentioned at the beginning – thanks!
Tolentino28 Jan 2021 15:58
The wooden ones are also much nicer and more practical than the other types.
K1300S29 Jan 2021 06:43
The question is how they will look after being in a wallet for years. 😉
G
guckuck2
29 Jan 2021 08:12
The token you already carry with you is practical anyway
untergasse4329 Jan 2021 10:06
A chip implanted in the hand is the only consistent solution (and I actually mean that seriously).

I’m hoping that I can also use the COVID chip for other purposes. If, for example, Bill Gates had also included MIFARE DESfire, I could use it to unlock ekey locks 😀 😀 😀 (that part was probably not so serious).
K
knalltüte
29 Jan 2021 10:28
Yes. We still need to address the security aspects of RFID and the tokens. Reading the token is at least not an issue (using a tool or mobile app...).
G
guckuck2
29 Jan 2021 11:31
What kind of tokens are those, if you claim to be able to read them?

Or to put it another way: If the door station uses such insecure transponders, it’s basically useless.