Zigbee soil sensor
measure ground moisture and temperature
Introduction
I was looking for an outdoor sensor to measure the ground humidity to see if I need to water the plants outside.
I found this soil sensor, with a solar panel, which could do the job!
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Table of Contents
Specifications
These are the specifications for this sensor:
| Key | Value |
|---|---|
| Battery | AA 1.2V * 3 Ni-MH battery (Rechargeable) |
| Solar Charging Current | 35mA |
| Communication Protocol | Zigbee 3.0 |
| Wireless Protocol | Zigbee IEEE 802.15.4 |
| Wireless Distance | 50M |
| Waterproof Level | IP66 |
| Temperature Detection Range | -10～60℃ (14℉～140℉) |
| Moisture Detection Range | 0～100%RH (Non-Condensing) |
| Maximum Detection Range of Electrical Conductivity | 20ms/cm |
| Temperature Detection Accuracy | 0.5℃ (Adjustable) |
| Moisture Detection Accuracy | 5%RH (Adjustable) |
| Electrical Conductivity Detection Accuracy | 3%FS 0.01ms/cm |
| Time Span of Detection | 10min (Adjustable) |
| Working Temperature | -10 ~ 60℃ (14 ~ 140℉) |
| Working Humidity | 0 ~ 100%RH (Non-Condensing) |
| Size | 78mm x 78mm x 146mm |
Zigbee soil sensor (AliExpress)
| 
NAS-STH02B2
Installation
To install it, press only the metal pins full in the ground.
If you have a model which is battery powered, you can reach those via the bottom and unscrew the panel.
Zigbee2MQTT
The model is registered as NAS-STH02B2 in Zigbee2MQTT.
To pair it, there is a button underneath the head that you need to press for a few seconds to get in pairing mode.
{
"battery": 81,
"ec": 1,
"fertility": "normal",
"humidity": 0,
"humidity_alarm": "lower_alarm",
"humidity_sensitivity": 2,
"last_seen": "2025-01-12T10:01:00.904Z",
"linkquality": 94,
"max_humidity_alarm": 70,
"max_temperature_alarm": 40,
"min_humidity_alarm": 20,
"min_temperature_alarm": 10,
"schedule_periodic": 5,
"temperature": 16.4,
"temperature_alarm": "cancel",
"temperature_f": 61.5,
"temperature_sensitivity": 0.5
}
Home Assistant
The sensor generates a lot of entities, but the main ones are temperature and humidity. There are a lot of alarms you can define and end up as entities.
The temperature and humidity can be added on the dashboard.
These settings can be changed.
Buy
Are you also excited about this sensor? Here you can buy it yourself.
Zigbee soil sensor (AliExpress)
See here for more outdoor Zigbee devices!
Other plant sensors
Other Zigbee sensors to track your plant health!