Xiaomi thermohygrometer: how to connect to a smartphone in 5 minutes

Xiaomi Thermohygrometers (e.g. Mijia Bluetooth Temperature and Humidity Sensor 2 or ClearGrass) CGDK2) These compact devices allow you to track temperature and humidity in real time, sending data directly to your smartphone, but many users have difficulty connecting first: The sensor is not detected, the application is giving an error, or the indicators are not updated. In this article, we will discuss all the ways of pairing a thermohygrometer with a phone, including nuances for different models and operating systems.

It is important to understand that the connection process depends on the device’s communication protocol: new models (e.g. ClearGrass) CGG1) working with Bluetooth Low Energy (BLE), And old ones (like Mijia). LYWSD03MMC) We'll look at both options, and we'll give you recommendations on how to best place the sensor and adjust the notifications. If you've just unpacked the device and you don't know where to start, this guide is for you.

What models of thermohygrometers Xiaomi are and how they differ

Before you connect, you should specify which model you are holding, which depends on the pairing requirements and functionality.

• 📱 Mijia Bluetooth Temperature and Humidity Sensor 2 (LYWSD03MMC) — most popular model BLE, It works without a gateway, supports firmware for integration with Home Assistant.
• 🌡️ ClearGrass CGDK2/CGG1 — Improved version with capacitive display, accuracy ±0.3°C and the possibility of calibration through the application.
• 🔄 Xiaomi Aqara Temperature and Humidity Sensor (WSDCGQ11LM) — requires an Aqara Hub or Mi Gateway gateway, but offers advanced statistics.
• 🔋 Mijia LYWSD02 — obsolete model with a replaceable battery CR2032, It is often found in the secondary market.

The main difference is the communication protocol:

- BLE-models, for example, LYWSD03MMC) Connect directly to your smartphone via Bluetooth 4.0+ They do not require additional equipment.

- Zigbee models (e.g, WSDCGQ11LM) They only work through the lock. Xiaomi/Aqara, but can be networked with other sensors (movements, door openings, etc.).

If you're not sure about the model, look at the label on the back of the device or on the package. LYWSD03MMC This is the second version of the sensor. BLE. You can also check by design: ClearGrass display occupies almost the entire front panel, and Mijia – a small screen in the center.

Preparation for connection: what to do before pairing

Before you start setting up, follow a few mandatory steps to avoid common errors, such as the invisibility of the device in the application or synchronization failures.

Install the Mi Home app (or Aqara Home for Zigbee models)

Enable Bluetooth and geolocation on your smartphone

Remove the protective film from the battery compartment (if any)

Place the sensor within a radius of 2-3 meters from the phone

Charge your smartphone to 50% or more-->

Pay special attention to the appendix:

- For BLE-models, for example, LYWSD03MMC) Use Mi Home (available for Android and iOS).

- For Zigbee models (e.g, WSDCGQ11LM) Aqara Home will be required + lock.

- If you plan to integrate with Home Assistant or Apple HomeKit, check compatibility in advance – some sensors require custom firmware (for example, a custom firmware, ATC1441 for LYWSD03MMC).

⚠️ Note: If you’re using an iPhone with iOS 13 and below, some Mi Home features may not work properly. Update to the current version or use your Android device to initially set up.

Also make sure the battery is installed correctly. In most models, it's already inserted, but it's protected by a plastic pad. Remove it with a paper clip or a toothpick, the sensor should squeak or flash the indicator. If there's no reaction, check the polarity of the battery (usually this is the case). CR2032 3B).

Step-by-step: how to connect thermohygrometer Xiaomi through Mi Home

The most popular model is the Mijia Bluetooth Temperature and Humidity Sensor 2 (LYWSD03MMC). The instructions are relevant for Android and iOS, but with slight differences.

1. Open the Mi Home app and log in (or register if you don’t have an account) and select Russia region (or your country) – this is important for the servers to work properly.
2. Press «+» → «Add the device" in the upper right corner. enter the model name in the search bar (for example, LYWSD03MMC) Or select the category "Sensors».
3. Hold the sensor to the phone at a distance of no more than 1 meter. Make sure that the sensor screen displays the temperature (if not, remove and insert the battery again).
4. Click "Plug" in the app. You'll start searching for the device (it can take up to 30 seconds). If the sensor isn't found, update your Mi Home firmware or restart your Bluetooth on your phone.
5. Select a room for the device (e.g., "Bedroom" or "Kids' room") and confirm the add-on. Ready! Now the data will be updated every 5-10 minutes.

If the sensor is not connected, try the following steps:

Reboot your smartphone and sensor (remove the battery for 10 seconds).

Make sure you have the original device – fakes are often not compatible with the Mi Home.

- Check if the antivirus is blocking or VPN Access to Xiaomi servers (disable them while you set up).

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If the sensor is detected but the data is not updated, try resetting it to factory settings. To do this, hold the button on the back (if any) for 5 seconds until the indicator blinks 3 times.

Connecting through the Xiaomi Gateway: When it is needed

If your model of thermohygrometer is Zigbee protocol (e.g. Aqara) WSDCGQ11LM), It can't be connected directly to your phone, and you'll need a gateway, a Xiaomi Gateway, an Aqara Hub, or a compatible device (like a Redmi Router). AX6S Zigbee-enabled).

Algorithm of action:

1. Connect the gateway to the socket and wait until it lights up in blue (pairing mode).

2.In the Mi Home app, add the gateway as a new device (Category "Gateways").

3. After successfully adding the gateway, press «+» → «Add the device" and select your thermohygrometer.

4. Bring the sensor to the gateway at a distance of 1 meter and wait for the signal (sound or light).

5. Complete the setup by selecting a room and saving the changes.

⚠️ Note: If you use an Aqara gateway, you will need the Aqara Home app to set up, not the Mi Home. Trying to add a sensor through an inappropriate app will result in the error "Device is not supported".

Set up notifications and automatic scripts

Once connected successfully, you can set up alerts and automation, for example, a sensor will alert you if the nursery humidity drops below 40% or the temperature in the greenhouse exceeds 30.°C.

How to set up notifications in Mi Home:

1. Open the device card in the application.

2.Push three dots in the upper right corner → «Notifications».

3. Enable the “Admonishments” option and set temperature/humidity thresholds.

4. Select the notification method: Push notification, SMS (Number binding required) or sound signal (if supported by a gateway).

To create automatic scripts:

1. Go to Automation (at the bottom of the Mi Home menu).

2.Push «+» → «Create a script».

3. Select a condition (e.g., "Temperature" > 28°C) and action (e.g., “Send notification” or “Set on air conditioner»).

4. Save the script and activate it.

Tip: If you use multiple sensors, give them unique names (e.g., Bedroom Thermogyrometer, Balcony Thermogyrometer) and make it easier to set up scenarios and analyze data in statistics.

Frequent mistakes and their solutions

Even with the right connection, users face problems.-5 errors and ways of eliminating them:

• 🔴 Sensor not found in Mi Home: - Check if Bluetooth and geolocation are enabled. - Update the app to the latest version. - Reboot the sensor (remove the battery for 10 seconds).
• 🔄 Data not updated: - Make sure the sensor is in range of Bluetooth (up to 10 m without obstacles). - Check the battery charge (at a discharge below 2.5V the device can glitch). - Reconnect the sensor in Mi Home (remove and add again).
• ❌ Error "Device not supported": - You have selected the wrong region in Mi Home (try changing to China mainland). - Device is fake or intended for another region (check out) QR-packet).
• 📵 Sensor shuts down after a few days: - This may be due to the phone's energy saving. Add Mi Home to battery optimization exceptions (in Android settings). - For iOS: turn on the option for Mi Home to Allow Background Activity».
• 🔋 Fast battery discharge: - Reduce the refresh rate of the sensor (e.g., from 5 minutes to 30 minutes) - Use batteries from well-known brands (e.g., Duracell or Energizer).

If none of these things worked, try resetting the sensor to the factory settings.

1. Remove the battery.
2. Press and hold the button on the back (if any).
3. Insert the battery back without releasing the button for 10 seconds.
4. Release the button when the indicator flashes 3 times.

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If the sensor still doesn't work, check it on another smartphone. If the problem persists, the device malfunctions (possible defect or damage during transportation).

Integration with Home Assistant and other smart home systems

Xiaomi’s thermohygrometers can be connected not only to the Mi Home, but also to other platforms such as Home Assistant, Apple HomeKit or Google Home.

For Home Assistant:

1.Install the Xiaomi component BLE Mi Home Integration through HACS.

2. Add the following lines to the configuration.yaml file:

sensor:


- platform: mitemp_bt




mac: 'XX:XX:XX:XX:XX:XX' # MAC- address of your sensor




name: "Bedroom Thermogyrometer"

3.Reset Home Assistant and check for new entities.

For Apple HomeKit:

- Use the Aqara Hub gateway M2 (It supports HomeKit natively or the HomeBridge plugin with a connected sensor via Mi Home.

In HomeBridge, add the homebridge-mi-hygrothermograph plugin and configure it according to the instructions.

For Google Home:

1. Connect the sensor to the Mi Home.

2.In the Google Home app, click «+» → «Set up the device» → «There are devices already?».

3. Select Mi Home from the list of services and log in.

4. Move the sensors to Google Home.

⚠️ Note: When integrated through third-party systems (e.g. Home Assistant), the sensor may stop showing up in Mi Home.This is normal - the data is now managed by another platform.

FAQ: Answers to popular questions