We already know about Sonoff’s SNZB-02 temperature and humidity sensor, but that was mainly used with something else. A sensor you can place where needed and forget about it. This time we get a bit more with a display and different mounting options to fit everyone’s needs.
In terms of functions it is almost the same as the non-display version, but I will talk about it in a moment in details. Size wise it measures 62,5mm x 59.5mm due to the display.
For the mounting option we get the usual 3M sticky with it for wall mounting, magnetic back mounting (on a fridge maybe?) and this time there is a tilting part to use it as a standing display anywhere near you. So we can have the mounting base with the 3M sticky on a wall and if needed, simply slide it out and use the magnet or the stand to mount it wherever needed even temporary.
Price wise at $12.99 it is a great option for a Zigbee sensor with display in our smart home setup.
What can it do / How accurate is it?
In terms of accuracy temperature and humidity are measured with 0.2% and 2% accuracy respectively with the SM60 series sensors and a refresh rate of 5 seconds. This is a new hardware option compared to the previous model.
It is using the Zigbee 3.0 protocol for connection and the MG22 IC to handle this. This is ths same IC as we can find in the ZBMini extreme (or ZBMini-L2) that just came out in January 2023 as the new ultra compact Zigbee smart relay.
What is Zigbee?
Zigbee is a communication solution specifically designed for low-power devices where high data bandwidth is not required, but where it is important to minimise the time delay. Zigbee is a good choice for battery-powered sensors, for example, where the uptime is several times that of WiFi. Zigbee devices are capable (under certain conditions) of mesh networking and can reach huge distances between two endpoints.
The Zigbee sensors cannot be used on their own, they need a Zigbee hub to connect them to your home/office network. One per system is sufficient, taking advantage of the above options.
It has a CR2450 battery inside and will last up to 2 years based on Sonoff’s claims, will put this part to the test 🙂
It is said to be working fine between -9.9 and + 60 Celsius degree and 5-95% humidity. I can hope this is true but as soon as it is getting cold, due to the battery in use it can go a bit unreliable…for me it was reporting low battery around 0 celsius degree.
Additionally we get an actual icon status display too as frosty, dry, wet, hot conditions based on what it measures.
The DATA
It is not just a display, but a data storage system too…ok, this may be a bit over exaggerating, bit it can display our data on a graph in the eWeLink app with hourly accuracy and we can also download the historical data of the last 6 months if needed. Hourly is not what you need for a detailed test, but should be enough to finetune your heating system for the long run.
Comfort settings
In the eWeLink app we can set up our comfort settings for the icon display. Not much extra, but nice to have a bit of control over what we personally consider hot or cold.
Push notifications
If we wish to set alerts, we can do that with the SNZB-02D. Simply use the eWeLink app and under the comfort settings menu you can set your desired alert levels. This could be great if you use it in an environment where a good balance for temperature and humidity is important.
Home Assistnt
As it uses the Zigbee 3.0 protocol I was able to connect it to my HA server with a zigbee usb stick without an issue.
Of course if you already paired it with your hub in the eWeLink app, you can simply use the official HA addon and sync the information without and issue.
Installation
- Launch your eWelink or Smart Life app where the Zigbee hub is already active and ready for battle.
- Find the add button and click on it in the app
- Remove the back of the sensor, check that the battery is not protected with a thin film, remove it
- There is a small button at the bottom of the device. Press and hold it for a few seconds.
- After a few seconds the top grid will flash red, indicating that it is in Pairing mode
- In 5-15 seconds they will find each other and your phone screen will display the relevant information
🆓 – I was interested in the product, I received it for testing
💵 – I got it for free, 100% my own opinion
