Sonoff SNZB-02DR2: Zigbee temperature and humidity sensor with display

Sonoff is relaunching a temperature and humidity sensor with display, a new version called SNZB-02DR2, which is proving to be a big hit in the smart home market.

Why does Sonoff SNZB-02DR2 have such a price?

Sonoff is a leading company in the Smart Home market with quality, complete and competitively priced products.

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Sonoff SNZB-02DR2 Tutorial

Today we will discover all the details of this new SNZB-02DR2 sensor.

General characteristics of Sonoff SNZB-02DR2

Sonoff had already introduced a temperature and humidity sensor called SNZB-02D which is the number 1 seller in the home automation shop where I work in terms of units sold.

And this new model is likely to be the number one seller by 2026 and there is no shortage of reasons for this.

In a house, heating is one of the most important aspects that we can optimise since, thanks to the implementation of products such as smart thermostatic valves for water radiators, on/off modules for electric radiators or smart thermostats, we can save up to 30% on our energy bill.

And to be able to have an adjustment of this heating, in many cases, we can use smart temperature sensors like this sensor from Sonoff.

We all have heating at home and, moreover, to optimise our energy costs, we can segment by controlling the heating in each room of our house.

Therefore, we usually adopt several temperature sensors and this Sonoff sensor has multiple advantages, which is why many users use this new model.

It communicates with the famous Zigbee technology and is compatible with different ecosystems such as Ewelink, Jeedom, Home Assistant and Zigbee2mqtt.

In addition to sending temperature measurements from -20 to +60 °C, it also communicates the humidity level from 0 to 100% RH, which is practical in some contexts such as ventilation management.

Another very interesting detail is that it integrates a display, so, in addition to sending its data to a compatible Zigbee hub, so you can see the measurements in real time on your phone and create routines according to your needs, you can also read the measurements in real time.

Like the previous model, we have real-time measurements of temperature, humidity level, battery level and a network icon.

But additionally, we now have maximum and minimum temperature and humidity levels for the last 24 hours.

We also have a larger 3.6-inch display, so we can more easily read the measurements from a distance.

Speaking of aesthetics, it is white in colour and measures 95x70x18.2 mm.

We have a stand to place it on top of a piece of furniture.

And another support if we want to hang it on the wall.

On the back, there is a button and pressing it once wakes up the device, twice allows you to change the unit from °C to Fahrenheit or the other way round and, when held down for 5 seconds, allows you to put it in association mode to link it to a Zigbee hub.

We also have the battery compartment, this time being 2 AAA batteries, which should give us longer battery life and being easier to find in the market.

And it is worth noting that if we use a Sonoff Zigbee hub, we can link a Sonoff indoor or outdoor temperature sensor and read the measurements from this sensor into our SNZB-02DR2 sensor, which can be interesting if we want to read the temperature in the garden or another room from our main sensor.

How to pair the Sonoff SNZB-02DR2 sensor

Speaking of Zigbee hubs, we are going to link this sensor, in my example, with the Home Assistant Green hub, with the ZBT-2 Zigbee antenna and the Zigbee2MQTT platform.

To link this sensor, we must activate the inclusion mode from our Zigbee hub.

Now, we can remove the battery protection and, after a few seconds, the sensor should automatically appear on the interface of our Zigbee hub.

So we will be able to enjoy its different functions.

Sonoff SNZB-02DR2 Sensor Features

To begin with, “Battery” indicates the remaining battery percentage of the sensor from 0 to 100 %, allowing us to know how much battery is left and to anticipate battery replacement.

“Voltage” is the battery voltage in millivolts (mV), which gives more technical information than the percentage, allowing to detect voltage drops.

“Temperature” is one of the main functions of the sensor: the current temperature measured by the sensor. This measurement will be updated every time there is a temperature change of plus or minus 0.2 °C within 5 seconds and with a measurement accuracy of plus or minus 0.2 °C.

“Humidity” is the other main function of the sensor, reporting the current humidity level from 0 to 100%, with a report within 5 seconds when there is a 1% change in humidity level, with a measurement accuracy of plus or minus 2%.

“Comfort temperature min” defines the minimum temperature considered comfortable. If the temperature falls below this value you have set, the sensor displays a snowflake icon on the screen.

This is used to visually tell when it is too cold.

“Comfort temperature max” is the opposite: the maximum temperature considered comfortable. If this value is exceeded, the fire icon appears on your screen.

You can set ranges from -10 to +60 °C.

“Comfort humidity min” sets the minimum acceptable humidity. If the humidity falls below this value, the sun icon appears on the display.

“Comfort humidity max” defines the maximum humidity considered comfortable. If it is exceeded, the device displays the drop icon.

The adjustable range is from 5 to 95% and is ideal for controlling areas that are too dry or to avoid excess humidity and prevent mould.

“Temperature units” allows you to choose the temperature unit shown on the display between °C and Fahrenheit.

“Temperature calibration” is used to adjust the accuracy of the temperature sensor. This means that you can add or subtract a value from -50 °C to +50 °C.

For example, if you have seen that the sensor measures 20 °C but it is actually 18 °C at home, you can calibrate it to -2 °C to get an accurate measurement by comparing it with a reference thermometer.

“Humidity calibration” allows you to correct the humidity reading with a positive or negative offset from -50% to +50% if you have seen an inaccuracy of the measurement.

And “Link quality” is the quality of your sensor’s communications with your Zigbee hub.

Sonoff states that this sensor has a direct range of up to 120 metres with your hub, but of course this is under ideal conditions, given that you will have various obstacles such as walls and furniture in your home.

So “Link quality” gives you a trend, with 0 being the worst value and 255 the best value.

We have already discovered how to improve this Zigbee LQI in a content about it, for example by adding different Zigbee devices connected to the power and thus forming a mesh network, automatically, between Zigbee devices.

It is worth noting that we will also be able to use this Sonoff sensor with Amazon Alexa voice assistants, being able to ask by voice the temperature measured at home, but we will not be able to ask the humidity level by voice.

And the whole point of this sensor is to be able to combine it with different smart devices, either modules that control electric radiators or ventilation, to reduce energy costs and improve comfort in our home.

Of course, Sonoff’s successes are due to the quality of its products, but also to the very competitive prices, being the case of this new sensor that you can find for less than 14 euros.

In short, this Zigbee temperature and humidity sensor with display from Sonoff is an essential new device for your smart home project, whether it’s to reduce heating costs, improve ventilation and optimise home comfort.

Generally purchased together

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