Sonoff Zigbee temperature and humidity sensor

Description

The Sonoff SNZB-02P is a Zigbee 3.0 sensor designed to accurately measure temperature and relative humidity in a Raspberry Pi-driven home automation setup. It comes in two variants:

• Standard version (no screen) : simple, compact format, ideal for discreet integration.
• Version with screen : features a small LCD screen to display readings locally, handy for a quick visual check.

Performance and accuracy

• Temperature : accuracy of ±0.2 °C.
• Relative humidity : accuracy of ±2 % RH.
• Data refreshed very frequently (up to every 5 seconds depending on configuration).

Long autonomy

• This sensor is powered by a coin cell battery CR2477, offering a battery life of around 4 years in typical use.
• It features an ultra-low-power design thanks to optimized Zigbee communication and stays in standby until the readings change significantly.

Design and installation

• Without screen : discreet, compact and lightweight housing (~45 × 45 × 17 mm, 27 g).
• With display : similar but fitted with a small LCD screen for local display, perfect for a room without a computer.
• Mounting with double-sided adhesive, screws or magnetic bracket.

Local Zigbee operation

Compatible with a Zigbee gateway (such as a USB dongle on a Raspberry Pi), it sends its readings automatically. It operates autonomously and enables:

• Local automations (via Home Assistant, Node-RED, MQTT…) even without an internet connection.
• Internal alerts : notification when a set threshold is exceeded.
• Data history and visualization in local dashboards.

Home automation uses with Raspberry Pi

• Automated climate control : switch on a fan or the ventilation system if the temperature exceeds a threshold.
• Indoor health management : alert if humidity is too high (risk of mold) or too low (dry air).
• Visual integration : the screen version lets you check temperature/humidity instantly without opening Home Assistant.
• Predefined automations : close the shutters at night if humidity is too low, trigger a humidifier, etc.

Robustness and consistency

• Operating temperature: -10 °C to +60 °C.
• Humidity: 5 % to 95 % (non-condensing).
• Designed to prevent false triggers and ensure reliable data over time.

Comparison