The basic set for a Xiaomi smart house- the gateway and ZigBee sensors. Basics of work.
The kit we are reviewing today includes next items:Xiaomi gateway,two windows/door sensors and wireless switch.
Why do we need a gateway? Little theory of ZigBee protocol.
ZigBee is a standalone network protocol designed for secure data transmission at low speeds and characterized by extremely low power consumption. It is advantageously different from Wi-Fi and Bluetooth 4+. A miniature CR2032 battery is enough for about a year of work!
The main feature of ZigBee is- that at extremely low power consumption it supports not only simple point-to-point (like Bluetooth) or star-like Wi-Fi structures – but also complex self-organizing and self-healing mesh networks, with relaying and message routing. What does it look like?
Let’s imagine a simple situation – one gateway and several sensors:
This is a classic “star” type network – where the central device is a gateway, which is responsible for the collection and processing of the commands from the sensors, and for the reverse sending of the control commands. The sensors do not directly “contact” and the gateway disconnection leads to the disconnection of all the sensors controlled by it.
Such a scheme resembles the work of a usual Wi-Fi home network – where there is a router instead of the gateway, and the laptops, tablet and phones are instead of the sensors.
Basically, this scheme is one of the most common, and it has been working well. However, there is a nuance. If there is a couple of walls or reinforced concrete walls between the gateway and the sensors, the weak transmitters may lack the power. It will be expressed in the periodic “rollover” of the sensors, or in their inability to work in the right place.
Now it’s time to remember the ZigBee protocol’s features – these are self-organization and retransmission. The role of such a repeater belongs to a smart socket – naturally of the ZigBee version, the version of Wi-Fi does not fit here.
In such a scheme, the socket will act as a repeater of the sensors’ signal, which will allow them to work at a distance from the gateway. This scheme has been checked by me, and it really works. Network topology changes automatically, all you have to do is plug in. Herewith, the state of the relay is irrelevant when it goes down/ turns off 220v for an external consumer.
Which devices require a gateway?
All wireless sensors -movement detectors, opening detectors, gas detectors, smoke detectors -need the gateway. If the sensor does not have wires, it works in acc. with ZigBee protocol (we are talking about the device for the Xiaomi smart house).
In addition to them, the above mentioned smart sockets apply ZigBee protocol. (but they have a twin brother with Wi-Fi – this is a stand-alone device), wire and wireless switches, Aqara built-in socket, and a motor for curtains from the same brand.
They all need the gateway- they do not work without the gateway, because ZigBee is a hardware protocol.
Everything else – Yeelight or Philips lamps, kettles, cleaners, extension cords, IR bases – mostly work via Wi-Fi, in some cases via Bluetooth. In any case, they do not need a gateway to work.
Xiaomi Multifunctional Gateway
The gateway is a “puck” made of white plastic, 8 cm in diameter with the thickness of 3,5cm.
The gateway has a Type I plug that is used in China, Australia and New Zealand. In european outlets it should be used via an adapter or extension cords with universal sockets.
There are speaker holes at the top of the gateway – as the gateway can serve as an online radio, a home alarm siren, an alarm clock, and also a light sensor hole.
There is a strip of translucent plastic at the front-end part of the gateway – this is an RGBW backlight.
First turning on/connection
After turning on, the gateway tells the rhyme in Chinese :), the backlight affectionately blinks and the device switches to the pairing modeю
The connection process is quite standard. The MiHome app detects a new device in range, suggesting connection. We choose our Wi-Fi network and the connection is finished.
After that, the gateway, if necessary, will downloads one or two firmware updates. The plugin management has quite a few different windows. The main one is the gateway’s backlight control window, where the color and brightness are set. Afterwards, when the sensors are added, a control panel with switches and sockets and a list of sensors-conditions (conditions of temperature, motion, opening, etc.) will appear in this window.
The second window contains alarm, doorbells, scheduled lighting control and alarm clock settings. There will be a list of all the scenarios in which devices controlled by the gateway participate. The third window contains a list of the connected devices. They may be added or deleted in this window.
Let’s look through the settings.
Entering the alarm settings menu, you can set the time of its operation, set the trigger – for example, an opening or movement sensor, but the sensor must be connected to this gateway, the interval can be set- that is the time that will pass after the sensor is activated and the siren is turned on, we can also set the sound and volume of the siren, as well as to view the trigger log.
Going to the automatic lighting menu, you can turn on the night light mode – the light will be automatically turned on in the dark, a trigger can be added- for example, a movement sensor, which will turn on the backlight, it is also possible to set the time of this trigger and the duration of the backlight.You can also turn on the light by the timer.
When you turn on the light by timer, you can select the repeat mode – for certain days, every day, once, set the work period and the color of the backlight.
The trigger condition is set in the doorbell mode -for example, pressing the wireless button, adjusting the type and the volume of the bell can be set, you can also set the sending of messages to the control gadget-for example, to the smartphone with Mi Home application installed. The alarm mode is very similar to the timer illumination mode, but the light is turned on here not the sound. This mode is interesting because you can choose not only the preset melodies but also upload your mp3 tracks. In order for the gateway to reproduce them at normal speed it should be encoded in 256 kbit.
Window/door opening sensors
The sensor consists of two parts – the sensor and the magnet. The magnet, when approaching the main sensor, closes the contacts of the reed switch – which makes it possible to fix the states – the state of opening and and the closed state.
In addition to the sensor there is a spare double-sided adhesive tape in the set; the tape is used for sticking the sensor on the surface of the door or the window.
The sensor is easily disassembled, and modified – due to the fact that the trigger is the state of the contacts.
We connect the sensor to the gateway through the Devices, pressing the button below – ”add subdevice”. Then following the prompts of the Wizard, with the help of a clip (that comes with the set to the gateway) we hold down the pairing button on the sensor, until the LED flashes three times. After that, you can choose the room of the location and the sensor icon.
This sensor does not have the control plug-in. There is something like a settings window with two tabs. The first one contains a list of the smart scenarios in which this sensor participates, as well as there are recommendations for using it -to turn off the air cleaner when opening the window and to turn on the light when the door is opened. The second one contains a log of sensor triggers.
When used in smart scenarios, the sensor acts as a scenario condition and has three variants of triggers – opening, closing and opening for more than 1 minute.
You can combine sensors connected to different gateways in one scenario, but in this case these scenarios will work only if you have the Internet. If the participants of the script are connected to the same gateway, or for example, the scenario action is to turn on the clever Yeelight or Philips lamp – the script will work without Internet connection.
Wireless switch button
Wireless button is one of the cheapest and most convenient sensors of the Xiaomi smart house system.
The spare double-sided adhesive tape is included into the set. You will need a clip o adjust the wireless button.
The button is added in the same way as the movement sensor, all the necessary actions are demonstrated by the Wizard.After pairing – it is necessary to choose the name and location of the button, after that it appears in the list of connected devices.
The settings window is similar to the one described in the opening sensor (the motion sensor, for example, or the cube, are the same), with two tabs – a list of scenarios and a trigger log. The button offers three actions for use in the scenario conditions: a single press, a double click and a long click.
Here is an example of a simple scenario – the switching on and off the Philips ceiling lamp.
The sensors we added appear in the main window of the gateway plugin, the planned (set) script is seen in the automation window.
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