A crisp e-paper temperature and humidity sensor - easy to read from almost any angle.
This sensor monitors temperature and humidity and reports back to your smart home system, so you'll know when a room is getting too toasty, too chilly or too damp. Keeping humidity in check helps head off condensation and mould, and spotting rooms that run hot or cold makes it easier to heat and ventilate your home sensibly.
The 2.9" display stays readable even in bright sunlight, and can also show the time, date, weather and readings from a second sensor (when connected to Home Assistant or a Sonoff Zigbee hub). Press the button to see the last six hours of history on screen, no app required. It runs on two AAA batteries (included) for 8+ months when connected.
This is a Zigbee device, so you'll need a compatible hub to use it with your smart home system - it won't connect directly to your Wi-Fi. If you don't have a Zigbee hub it will still show temperature, humidity and the 6-hour history.
Get Smart, Automate!
This is a smart sensor, so the fun really begins when you connect it to your home automation system.
Set up rules to switch on a dehumidifier when the bathroom gets steamy, or a fan when the office starts to bake. It can also act as an external temperature source for Sonoff's latest smart radiator valves, so your heating responds to the temperature where you're actually sitting, rather than the warm spot right next to the radiator. Depending on your platform, you can dig into historical data to see how each room behaves through the seasons.
Pair it with a Sonoff Zigbee hub such as the ZBBridge-P, NSPanel Pro or iHost and check readings from anywhere with the eWeLink app. It also works with Home Assistant on a Raspberry Pi or Home Assistant Green (with a Zigbee adapter), and other Zigbee 3.0 hubs including SmartThings and some Amazon Echo devices.
Features
- 2.9" e-paper display: Paper-like screen with a nearly 180° viewing angle that stays clear even in bright sunshine.
- All the essentials at a glance: Shows temperature, humidity, time, date, weather and comfort status, in °C or °F (double-press the button to switch).
- High-accuracy sensing: A Sensirion sensor gives ±0.2°C temperature and ±2% RH humidity accuracy, refreshing every five seconds.
- Remote sensor display: Show readings from another Sonoff sensor so you can check on the nursery or the greenhouse without getting up.
- Flexible placement: Fold-out stand, built-in magnet, wall hanging slot or adhesive mounting.
Tech Specs
| Model | SNZB-02UL |
| MCU | TLSR8258 |
| Input | 3V (2x 1.5V AAA batteries) |
| Battery model | LR03 AAA |
| Battery life | 8+ months connected, 15+ months standalone |
| Display | 2.9" E-Paper |
| Wireless connection | Zigbee (IEEE 802.15.4) |
| Net weight | 91g (including batteries) |
| Colour | White |
| Dimensions | 99.1x51.1x18.6mm |
| Casing material | PC |
| Applicable place | Indoor |
| Working temperature | 0°C~50°C |
| Temperature accuracy | ±0.2°C; ±0.4°F |
| Working humidity | 5~95% RH non-condensing |
| Humidity accuracy | ±2% RH |
| Certification | CE/FCC/RoHS |
| FCC ID | 2APN5-SNZB02UL |
Resources
Check out the SNZB-02UL knowledge centre for technical details, compatibility, troubleshooting and setup tips.
Notes
- Using Home Assistant? Temperature and humidity readings worked out of the box for us with ZHA, but the remote sensor display and weather data needed SONOFF's configuration files loading. Built-in support for these features is on the way.
- Like all e-paper displays, the screen may briefly flash when it refreshes, and it'll keep showing its last image even with the batteries removed. That's perfectly normal!
What is Zigbee?
Zigbee is a low-power wireless standard made specifically for smart home gadgets like sensors, switches and lights. It sips power so it's perfect for battery-powered devices that need to keep going for months (or years) between battery swaps.
Zigbee devices form a mesh network, with mains-powered devices like smart plugs and bulbs passing messages along for their neighbours. The more devices you add, the stronger and further-reaching your network gets.
It also works locally, so your devices keep chatting to your hub even if your internet decides to take the day off. That means snappier responses, better reliability and improved privacy. It's supported by loads of manufacturers too, so mixing and matching brands is no problem.
Want to learn more? Check out the official Connectivity Standards Alliance website.