Smarthome building systems technology / home automation / bus system

  • Erstellt am 2016-09-01 13:15:06

Mycraft

2018-03-02 09:59:22
  • #1
Motion sensors:





Motion sensors vs. presence detectors in comparison:

While presence detectors have to respond to the smallest movements, motion sensors are responsible only for monitoring extensive corridors, outdoor areas, or similar spaces. The primary task of motion sensors is to switch the light on when clear movements are detected, whereby this function can be programmed to depend on brightness. Additionally, the light stays on as long as movement is signaled and only switches off again when everything is still. Although the basic principle is identical with presence detectors, a special fine tuning has been made in this design, enabling the light to be turned off again when not needed. The finely mechanical sensor reacts to the smallest differences in brightness and, thanks to a high-resolution detection field, can turn the light on and off at its discretion. A detector that literally thinks along and makes everyday life easier. After all, you no longer have to think about the light. In fact, operating the light switch can be completely forgotten. Or light switches in transitional rooms (hallways, foyers, dressing rooms, staircases) can be completely omitted.

Here the internal construction of the two variants can be seen. The difference is clearly visible. Presence detectors have several PIR sensors. Motion sensors usually only have one.

Presence detector:




Motion sensor:

 

Almo85

2018-05-16 07:15:36
  • #2
Good overview of presence and motion detectors. Perhaps information about temperature sensors, humidity, or similar would also be interesting.

Best regards
Almo
 

Mycraft

2019-03-16 15:15:20
  • #3
Binary Inputs:

Binary inputs are simple devices that register binary events, meaning a 1 or a 0 (also On/Off), and can send them to the bus in order to, for example, output a status message or trigger other functions.

A counter function, for example for water consumption, can easily be realized using a binary input if one has a water meter with a pulse output or reed contact.

Binary inputs are usually available as REG built-in devices with 4/6/8/16/32 inputs, or as flush-mounted versions (also called push-button interface) with 2/4/6 inputs. Of course, other channel numbers can also be found, but these are the most common. Another difference is that there are binary inputs available for 230V alternating voltage, for 0-30V direct voltage, and also potential-free versions.




Anything that can open/close a contact can be connected to the binary inputs, and through the binary input this information is then available on the bus and, according to the programming, also to switches, displays, or other output devices.

Thus, in addition to the mentioned water meter, one can also transfer status information from window/door contacts, leak detectors, smoke detectors, fill levels of cisterns, or a common standard light switch to the bus.
 

Mycraft

2019-12-05 18:37:27
  • #4
Temperature Sensors:

Standalone temperature sensors with direct KNX connection for indoor or outdoor use are rare or practically never available for under 50 euros (each). With other bus systems, this is significantly cheaper, and therefore, in KNX, other systems for temperature detection such as 1-Wire may be used if necessary and depending on the situation.

However, temperature sensors are also built into room temperature controllers, presence detectors, touch sensors, or other bus participants with appropriate equipment, and these can be used accordingly. The advantage of direct KNX-capable temperature sensors is that they can be calibrated directly and often come with a lot of additional features from the manufacturer. It is not just a "dumb" temperature sensor but an independent device with an evaluation unit, statistical functions, logical operations, etc.

There are also REG and UP devices that allow the connection of several temperature sensors, making the price per temperature measurement point overall cheaper.

Here are a few examples:






 

Mycraft

2019-12-07 11:13:14
  • #5
In addition, there are suitable sensors for every task available for the various systems in building automation technology.

These include: humidity sensors (often combined with temperature), mixed gas/air quality sensors (often combined with CO2), leakage sensors, lux meters, anemometers, pH value, global radiation, current and voltage, rain and soil moisture, water level, vehicle detection, laser rangefinders, or optical sensors of various kinds and tasks.

Sensors are often combined, as this saves an additional evaluation unit and allows several environmental influences to be measured and transmitted at once. This, of course, lowers the price for the end customer and increases attractiveness.

All of this increases the overall functionality of the system and thus creates "eyes and ears," enabling the house/apartment to independently make decisions locally in response to occurring events. Previously defined parameters can be executed rigidly or flexibly, e.g., by means of hysteresis or self-learning algorithms. For example, the performance of the ventilation system can be increased when cooking takes place, or garden irrigation can be turned off during rain or not started at all because rain is expected.

Here are a few examples.


Temperature/Humidity/Climate

[B]Sensor / Controller for Water Quality [/B]


[B][B][B][B][B]Global Radiation Sensor[/B][/B][/B][/B][/B]


Humidity, Temperature, [B][B]Soil Moisture
[/B][/B]


 

Mycraft

2019-12-10 13:37:59
  • #6
Gateways in an automated/"intelligent" house:

A gateway is somewhat of a gate, but at the same time also a key. With its help, different computer networks and various technologies are connected regarding their connectivity so that they can continue to communicate and work together. Among other things, different protocols are connected, but also synergies between different devices are created: for example, emails into fax or SMS into emails. For a house to become "smart," "intelligent," or whatever else, gateways are necessary. Because the manufacturers of the end products do not make it easy, and each, of course, has its own system, which it favors for whatever reasons at the moment.

A smart home is known to be a home in which technical components are networked with each other, can be controlled centrally and decentrally, and at the same time can develop synergies with each other - for example, when the lighting automatically turns on when the door opens or when the absence mode and the alarm system are activated when leaving the house. Whoever controls the lighting with a smartphone (e.g., with Philips Hue or Osram Lightify) or can electrically lower their blinds (e.g., with Somfy TaHoma) does not automatically have a smart home, but rather a modern, technical installation. For it to actually be classified as intelligent and clever living, it must develop synergies and react to each other - this works, among other things, with the help of gateways.

The more varied components there are in the smart home that use manufacturer-specific communication methods, the more the number of gateways that must communicate with each other increases. Since there is no uniform standard for all devices worldwide, we can use one (or more) mnemonics in the form of globally valid standards for communication protocols (TCP/IP, KNX, Z-Z-Wave, Bluetooth, WLAN, Modbus, etc.). This allows any components on the hardware and software level to be connected and controlled, configured, and monitored from one application, e.g., a browser.

Gateways exist in various forms and variants as hardware or as software components.

Some systems take the inconvenient route and try to fit as many gateways as possible as a "universal gateway" into one device. This often results in the end customer having to pay for unnecessary functions and/or devices functioning unstably and prone to failures. Having a separate gateway for each protocol is much more elegant and has the advantage that the full functionality of each communication channel can be used (if desired/wished) and is not limited, as bandwidth, etc., are intended for another.

Here is a list of which protocols and manufacturers can be connected nowadays. The devices of the manufacturers can then "talk" to each other, for example, via the KNX medium. (Of course, much more is possible, but that would go beyond the scope here)

z-Z-Wave, zigBee, EnOcean, Bluetooth, Homematic, WLAN, DALI, CAN, LON, M-BUS, RS232, RS485 TCP/IP, IoT (Alexa, Sonos, and co.), HTTP, MQTT, SNMP, DMX, MODBUS, BOSCH 4A, 1-Wire, effeff BCM925, EsserNet, Honeywell MB100.10, Warema, Somfy, Hue, Hörmann, Velux, Daikin, Becker, ekey, AMX, Crestron, Panasonic, Axis, Berbel, Miele etc.

Furthermore, there are various software concepts that can perform similar tasks on a Raspberry Pi, such as: IPSymcon, SmarthomeNG, Openhab, FHEM, ioBroker, Homekit, etc. However, the software solutions take the path of total control and are virtually placed on top of the system. Thus, all communication is monitored, controlled, and supplemented if necessary with logic functions. The disadvantage here is that if the server fails, everything is out of operation at the same time and usually can only be operated manually. In decentralized systems, everything never fails completely (except in a power outage, but even here precautions can be taken), and thus the chance of a total failure is more than low.

 

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