Budget Zigbee Motion Sensor Sonoff SNZB-03: Review & Connection in Tuya Smart and Home Assistant 2022.
The topic of this review will be the budget SNZB-03 motion sensor from the Zigbee series of smart devices from Sonoff. For its cost, it is a great option for those who are not confused by the utilitarian design of the gadget.
- Model: Sonoff SNZB-03
- Interface: Zigbee 3
- Detection range in a straight line: up to 6 meters
- Sensor viewing angle: 110 degrees
- Battery: CR2450
- Operating temperature range: -10 + 40C
- Size: 35 x 39 x 28mm
- Weight: 19 grams
- Separately, you can purchase a swivel leg – stand
The device is delivered in a typical orange box for this series. As you can see, on my copy, it looks like someone was trying to sit down. Nevertheless, the sensor remained intact. The box indicates the type and model of the sensor, as well as brief technical specifications.
In the unfortunate, but still fulfilling its functions, the box was found – a motion sensor, a piece of double-sided tape for fixing on the surface, a booklet with instructions and a card about passing quality control.
The instruction, although small, is still multilingual, and there was a place for a description in English. From what you need to know – to switch to pairing mode, you will need a paperclip, as for sim trays.
As I have already mentioned, the appearance of the sensors of this series is peculiar and easily recognizable. The body of the device is square, well, almost square, a couple of corners are slightly beveled. On the front part there is a hemisphere of the motion sensor.
On the back – it is supposed to attach the complete adhesive tape here, the model number and the type of battery are indicated. This cover is removable.
On the conventionally lower side – there is a hole behind which the button for switching on the pairing mode is hidden. Its activation takes the device out of the zigbee network, if the sensor is already in it.
The lid sits quite tightly, to remove it you need to pry it off with something – a special slot is provided for this. Under the cover there is a battery – a CR2450 battery, in the transport position – a special insert protects it from discharge. Arrows are marked on the body and the cover, which must be aligned – in order to install it correctly.
Let’s move on to the connection, for this we need a similar clip, it is not included in the kit, the readiness of the device for pairing is confirmed by the triple blinking of the red LED inside the hemisphere.
I’ll start the logical part right away with Tuya Smart, since Ewelink is not widely used. To connect, we need at least one Zigbee gateway, I use the Ethernet version from Moes. We launch its plug-in, press add a child device, and after activating the pairing mode on the sensor, press the button – the LED is already blinking.
The process of passing the interview and connecting takes less than a minute – the sensor appears in the window of detected devices, although here it is shown in a slightly different form and after specifying the name and location, it enters the gateway list.
Both from the gateway list and from the general list of system devices – by clicking on the sensor we get into its plug-in, which displays its status – accordingly, there is movement or not. Such a sensor belongs to the category of binary ones – since it can have only 2 variants of value.
The plugin has a trigger log, which shows that the interval of events is 1 minute. You can turn on the notification mode for each trigger. In the properties of the device there is no data on compatibility with third-party systems, and this is so – in Google Home, for example, the sensor did not appear. Be sure to check for a firmware update.
The motion sensor can only participate as a trigger or an automation condition. And for this, either the state of its battery can serve, for example, to warn about a low level of charge.
Or the actual motion sensor itself. In addition to the options – the presence and absence of movement, there are also options for time intervals – when there is no movement. The most common scenarios with such a sensor are turning on the lighting when motion is detected, and turning it off when it is absent, usually some 5-10 minutes interval is chosen.
Let’s move on to alternative systems and start with the SLS gateway. Connection according to the standard scheme – activate join in the gateway, press the sensor button with a paper clip and wait. It is defined correctly, with the corresponding model and picture.
Then the motion sensor appears in the general list of gateway devices. When the Home Assistant MQTT Discovery option is enabled in the gateway settings, it will automatically create a new device in the MQTT integration.
Here is all the sensor data from the info tab. Like other similar devices powered by a battery, it is an end device with a transition to sleep mode and is not able to broadcast data from other network participants through itself.
From the very beginning, not all parameters that the sensor is capable of transmitting appear, they will be updated as data is received from it.
After a while, data on the battery charge appears and this is how the complete list looks like – motion sensor, charge levels and signal quality, timeout for motion detection – by default 60 seconds and the parameter of the last response from the sensor.
These parameters in the form of 5 separate entities appeared in Home Assistant – one belongs to the domain of binary sensors, this is a motion sensor – the rest are sensors.
As for Zigbee2mqtt, there are no surprises here either. We start the mode of attaching new devices, and on the sensor we hold down the button with a paper clip until the red LED blinks three times.
Data from the information page – the manufacturer and model are correct, the end device. Everything is as it should be.
There are also 5 parameters here as in the SLS. Only instead of lastseen and timeout, there is a tamper and a parameter indicating a low battery charge. Included to the standard charge level.
There is a retain option on the settings tab, unless of course it is enabled in the general add-on config file. When it is activated, the values from the sensor will be saved in the MQTT topics and will not disappear, until the update, when the home assistant is restarted
As for Home Assistant – the described 5 entities appear in the system through the mqtt integration. There are three binary sensors – motion, tamper and battery discharge and two conventional, so to speak, sensors – signal and charge levels.
As for the time interval from the registration of the last movement to the reset, it is also one minute. This must be taken into account when planning automation.
Now a few words about my use case. The sensor shows itself well with such an installation – when the sensor looks in a horizontal plane. The sensitivity is good, about 5 meters in a straight line – it catches movement.
Personally, I paired it with the Aqara motion sensor installed in the kitchen. It is installed parallel to the wall, on the side of the air conditioner and catches movement right when entering the room, even a little earlier near the doorway itself. However, he does not see the rest of the kitchen.
I placed the hero of the review on the wall approximately in the middle, so that it covers as much as possible everything that Aqara does not see.
This is how they are located one relative to the other.
Aqara – catches everything that happens at the entrance, and even in front of the door itself, the angle is set so that when you enter, the light is already on.
And Sonoff – does not let it go out while there is movement in the room, including covering all the dead zones of Aqara,
As for the logic of work, for the motion sensors I created their virtual copies – in the form of template sensors. One for each room.
Having registered template sensors in automation once, there will no longer be any need to change them, even when replacing physical sensors, since they will be indicated only in one place – in the template, and the name of the template sensor will always be the same.
In addition, in such a sensor, you can combine several physical sensors, as in this example, or add some other conditions – for example, sensors for the time of day, illumination, status of certain devices, or set the required delay for turning on or off. Complete flexibility.
This is what this sensor looks like in automation. The structure is completely standard, but in fact, the same entity will always be used here – even if you completely change your device base, and it can include an essentially unlimited number of physical sensors and the necessary conditions.
During the observation of the sensor, I did not observe any oddities or deviations in its operation. Everything works as stated. The advantages of the sensor include its price, the disadvantages – a very controversial design.
That’s all, I hope that the review was interesting and useful to you.