Tuya Zigbee Plant Soil Sensor GXM-01 Review

As some of you may know, I test a wide variety of home automation hardware on smarthomescene’s AliExpress Reviews channel. Anything from simple switches and sensors to valve controllers and air quality sensors can be found on the Reviews page, with a purpose of separating quality products from trash/fake devices.

In an effort to cover interesting gadgets, I bought a temperature & moisture soil sensor, labelled model GXM-01 which I will teardown, test and integrate in Home Assistant.

This device can be bought for ~$30 on AliExpress and a bit more on Amazon.com.

Technical Specification

• Power Supply: 2xAA Batteries 1.5V
• Battery Life: ~ 1 year
• Humidity Range: 0~100%
• Humidity Accuracy: 0~50% (±3%), 50%~100%（±5%）
• Temperature Range:-20°C~60°C
• Temperature Accuracy: ±1℃
• Waterproof Rating: IP67
• Communication: Zigbee 3.0
• Product Size: 180x46mm, (60mm probes)
• Application: Gardens, Potted Plants, Farms, Orchards

Disassembly

The Tuya Zigbee Soil Sensor GXM-01 comes packaged in box containing only the sensor and a manual. It surprised me the box containing the sensor was stuffed inside a plastic air-filled cushion which was packaged in a corrugated cardboard box. The seller went the extra mile in protecting this device from shipping damage.

On the front of the body, some instructions for pairing the device are printed and the button is placed in middle. On the backside, the battery cover is held in place by 4 screws.



Removing the 4 screws reveals the battery chamber which holds 2xAA batteries, meant to last ~ 1 year. There is a small rubber loop on the cap which seals shut the battery compartment and protects them from moisture, hence the IP67 rating.

For reference, the 6 indicates “complete protection against dust over extended time” as well as “protection against contact with objects greater than 1mm in diameter, such as a wire or a small tool.” The 7 indicates the system is “protected against short periods of immersion in water while under pressure between 15cm and 1m.” 

“Water-resistant” means that the system protects against water entrance to a degree, but it does not offer complete protection.

Underneath the battery compartment, the main PCB can be seen containing the Zigbee communication module. It’s a Tuya developed ZTU-IPEX chip [Datasheet] embedded with a low-power 32-bit CPU, 1024-KB flash memory, 64-KB RAM, and rich peripheral resources.

Unfortunately, I could not disassemble the device further without completely ruining the IP67 rating, which is crucial for this device. It meant prying it open by force, which would have broken the seals on the top and bottom caps and render the product unprotected against moisture. Everything was sealed shut with glue, so there was no getting in without breaking it completely.

Here’s a photo of the device in one of my wife’s neglected plants, hopefully this soil sensor helps revive it by reminding her to water it more frequently.

Home Assistant Integration

This Tuya Plant Soil Sensor GXM-01 is officially supported in Zigbee2MQTT and ZHA in Home Assistant. To pair it, install a pair of AA batteries and hold the button on the front for ~5sec until the blue LED starts blinking rapidly.

Zigbee2MQTT

Once added to Zigbee2MQTT, the device is identified as model TS0601_soil and manufacturer _TZE200_myd45weu. Considering it’s a battery operated sensor, it is correctly set as an EndDevice. It exposes the following entities in Home Assistant via Zigbee2MQTT:

• select: Temperature unit °C or °F
• sensor:
  • temperature: Temperature reading °C or °F
  • soil_moisture: Moisture reading in %
  • battery_state: Battery level (low, med, high)
  • battery_percentage: Battery level in %

It is also possible to calibrate the temperature reading using the exposed cluster in Settings (Specific) and set a temperature precision by up to 3 decimal points.

ZHA

The Tuya Soil Plant Sensor GXM-01 is supported in ZHA too, automatically enabled with a custom quirk: tuya.ts0601_sensor.TuyaSoilSensor. It is correctly identified as an EndDevice with Zigbee Model TS0601 and Manufacturer _TZE200_myd45weu.

The device reports it’s temperature and moisture readings, as well as battery percentage. Additionally, signal quality in LQI and RSSI can be enabled if needed. No calibration is available in ZHA, you would have to create a template sensor with a specific offset if you find the readings to be incorrect.

Usage

The use case for this Tuya Soil Plant sensor is pretty obvious: measure soil moisture and temperature to keep your plants or garden alive and happy. You stick the device in the soil next to your plant and observe the reading in Home Assistant.

Different flora can have very different needs regarding moisture and temperature and for some, maintaining these values within their optimal range is crucial for the survival of the plant.

In my test, I purposefully chose a slightly neglected plant to monitor it’s moisture to see if I can spruce it up and revive it. After watering it for 3 days, here’s how my Home Assistant chart looked like.



The spikes in the chart are me pouring a cup of water inside the plant pot. It was immediately detected and reported by the device. The LED blinks when there is a sudden moisture change, indicating it’s sending a Zigbee payload. The smaller increases in moisture readings are me pouring a tiny spoon of water, to see if the sensor will pick it up, which it did.

I currently do not own any other soil moisture sensors to be able to compare the readings of this Tuya model GXM-01, to prove or disprove their accuracy. Because of this, I can only make assumptions and observations. Even though no clusters are exposed for moisture calibration in Z2M or ZHA, any offset can be easily set by creating a simple template sensor:

template: #Calibrate moisture by +5
  - sensor:
      - name: "Moisture Calibration"
        unit_of_measurement: "%"
        value_template: "{{ (states('sensor.soil_moisture') | int + 5)}}"
Code language: YAML (yaml)

Verdict

The Tuya Zigbee Plant Soil Sensor GXM-01 is an interesting temperature and moisture meter with a really useful and practical application. I installed a pair of old AA batteries from a TV remote, which gave me some pairing trouble initially but after installing a fresh pair, it paired immediately to my coordinator and I encountered no subsequent Zigbee communication issues.

I was unable to completely pry open the device without ruining it’s water resistance IP67 rating. It was completely glued shut and wouldn’t budge. Using more force meant I will potentially break the case caps and render it vulnerable to moisture or rain if installed outside.

This device is not the first of it’s kind, there are some DIY solution floating around as well as the bluetooth-based Xiaomi MiFlora Soil Sensor. In Summary:

Buy

If you have some potted plants at home or maybe a garden or an orchard, this device can be a good addition to your smart home. It’s currently sold for ~$30 on AliExpress and Amazon.