How to connect the thermometer Xiaomi to Mi Home: instructions with photos and tips

Xiaomi thermometers are some of the most popular smart home sensors due to their accuracy, compactness and integration with the Mi Home ecosystem. However, connecting these devices often raises questions: the app does not see the sensor, the indicator flashes in an incomprehensible way, the data is not updated. In this article, we will analyze all the stages of connection from unpacking to setting up automatic scripts, and also consider typical errors and how to fix them.

Feature of Xiaomi thermometers (for example, models) LYWSD03MMC, MHO-C401 ClearGrass is based on Bluetooth Low Energy protocol (BLE), This means that they need a Xiaomi gateway (such as Mi Gateway 3) or a smartphone with support to connect them. BLE. Without it, the sensor simply can't transmit data to Mi Home. If you already have a gateway, great, if not, we'll tell you how to do without it.

Important: the instructions are relevant for Mi Home version 6.6.0+ (2026) If you have an older version of the app, some menu items may differ, and note that Xiaomi thermometers do not support direct connection to Home Assistant without additional plugins – this will require Mi Home Integration or BLE-bridge.

1.What Xiaomi thermometers are compatible with Mi Home?

Not all Xiaomi temperature sensors work with the Mi Home, and here is the current list of supported models for 2026:

• 🔹 Xiaomi LYWSD03MMC — The most popular display option, which maintains humidity and temperature, works through the gateway or directly with the smartphone (but with limitations).
• 🔹 Xiaomi MHO-C401 — compact sensor without a screen, requires a gateway, supports a long life (up to 2 years from the battery) CR2032).
• 🔹 Xiaomi ClearGrass CGDN1 — waterproof (IP67). Compatible with Mi Gateway 3.
• 🔹 Aqara Temperature and Humidity Sensor – alternative from sub-brand, operates through the gateway Aqara Hub.

⚠️ Attention: Sensors LYWSDCGQ (The old model is not officially supported in the Mi Home since 2023, and can only be connected via third-party firmware (for example, by the new model, ATC1441) or Home Assistant.

If your model is not on the list, check its compatibility on the official Mi Home website or in the documentation for the device, LYWSD02) require firmware from third-party developers, which may deprive you of warranties.

2.Preparation for connection: what should be done before the start?

Before you start connecting, make sure that all the prerequisites are met:

Install the latest version of Mi Home (6.6.0)+)|Check the battery charge in the sensor|Connect Xiaomi Gateway to Network (if required)|Enable Bluetooth and geolocation on your smartphone|Make sure your smartphone is connected to 2.4GHz Wi-Fi-->

Pay special attention to the app version. Older versions of the Mi Home (up to 6.0) may not support new sensors. Update the app via Google Play or App Store, and if you have a Xiaomi smartphone, check for updates to Settings → The phone. → Updating the system.

⚠️ Warning: If you connect the sensor through the gateway, make sure it is within a 10 metre radius of the thermometer.Walls and partitions can degrade the signal BLE, Therefore, for reliable operation, it is better to place devices in one room.

Also check the region in Mi Home. By default, the app can be set to China, which limits functionality.

1. Open Mi Home and go to profile (top right corner).
2. Click on the country at the top of the screen (e.g., "China").
3. Choose “Russia” or “Europe” (depending on your location).
4. Restart the app.

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If the sensor stops showing after the region changes, remove it from the app and add it back, and the data from the previous period will be stored in history.

3. Step-by-step instruction: how to connect the thermometer to Mi Home?

Let’s look at the connection process on the example of Xiaomi LYWSD03MMC — For other sensors, the steps are similar, but small details may differ (e.g., the time to hold the reset button).

Step 1: Removal and activation of the sensor

Take the thermometer out of the package and remove the protective film from the battery compartment (if any). CR2032 (It comes in the kit, plus up. The sensor has to squeak and flash the blue light.

Step 2: Adding the device to Mi Home

1. Open Mi Home and go to the Device tab (bottom of the screen).
2. Press + → Add the device.
3. In the search box, enter the model name (for example, LYWSD03MMC) or select the category Sensors → Temperature and humidity.
4. Click on the device found and follow the instructions on the screen.

Step 3: Connect via gateway or smartphone

There are two options here:

• 📱 No Gateway (direct connection to smartphone): The sensor will only transmit data when you are near (radius) ~10 (m) Data are updated on a daily basis 1-2 Suitable for temporary use.
• 🌉 Through the Xiaomi gateway: the sensor connects to the gateway BLE, The gateway transmits data to the cloud. 5-10 Recommended method for continuous monitoring.

If you choose to connect through the gateway:

1. Make sure the gateway is already added to Mi Home and connected to Wi-Fi.
2. In the process of adding a sensor, the application will suggest choosing a gateway - select the desired one.
3. Bring the thermometer to the gateway at a distance of less than 1 meter and wait for the synchronization to be completed (the indicator on the sensor will stop flashing).

Step 4: Set up notifications and automatic scripts

After successful connection, you can configure alerts about critical values of temperature or humidity:

1. Open the sensor card in Mi Home.
2. Click on the three dots in the top right corner and select Notifications.
3. Set thresholds (e.g., "Warn if temperature is present") > 30°C").
4. Save the settings.

To create automatic scenarios (e.g., turning on the heater when the temperature drops):

1. Go to the Automation section in the lower menu.
2. Press. + → Create a script.
3. Select the condition: Temperature [your sensor] < 18°C.
4. Add the action: Turn on [smart socket/heater].
5. Save the script.

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If the sensor is connected through a gateway, the automation will work even when you're not at home, and if you connect directly to your smartphone, the scripts only work when you're using active Bluetooth.

4. Typical errors and their solutions

Even with the right connection, users often face problems.

⚠️ Warning: If the sensor shows temperature after connection -40°C or 99°C, this means a data read error, and most often the problem is solved by rebooting the sensor (remove and insert the battery) or updating the lock firmware.

Another common problem is that the sensor periodically disappears from the Mi Home. BLE: If the signal is weak, the connection may break:

• 🔌 Move the gateway closer to the sensor (optimally within 5 meters).
• 📶 Make sure there are no interference sources nearby (microwaves, other Bluetooth devices).
• 🔄 Reconnect the sensor: remove it from Mi Home and add it again.

If nothing works, try resetting the gateway to factory settings (hold the button on the gateway for 10 seconds until the yellow indicator blinks). After reset, you will have to reconnect all devices.

5. How to integrate Xiaomi thermometer with Home Assistant?

If you use Home Assistant to control your smart home, the Xiaomi thermometer can be connected via official Xiaomi Miio integration or BLE Monitor. Here's a quick guide:

Method 1: Through Mi Home (Cloud)

This method requires that the sensor is already connected to the Mi Home:

1. In Home Assistant, go to Settings → Devices and services.
2. Click Add Integration and select Xiaomi Miio.
3. Enter the username and password from your Mi Home account.
4. Select a region (e.g., Russia).
5. After synchronization, the sensor will appear in the list of devices.

Method 2: Through BLE (locally)

You will need a Bluetooth adapter on a device with a Home Assistant (such as the Raspberry Pi 4):

1. Establish integration BLE Monitor through HACS.
2. Add to configuration.yaml: ble_monitor: devices: - mac: "58:2D:34:XX:XX:XX" # MAC-Address of your sensor name: "Bedroom Thermometer"
3. Reboot Home Assistant.
4. The sensor will appear in the Entities section.

⚠️ Note: When connecting locally through BLE data are updated more frequently (once in a 1-2 minutes, but MAC-The sensor address may change after the battery is replaced, and then you'll have to update the configuration.

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To find MAC-Sensor address, use the nRF Connect app (Android/iOS) or hcitool lescan command in the Linux terminal.

6. How to extend the battery life?

Xiaomi thermometers are known for their low power consumption, but when used improperly battery CR2032 It can run out in a few months. Here's how to extend her life:

• ⚡ Turn off unnecessary notifications – every alert in Mi Home wastes charge.
• 📶 Reduce the frequency of data updates – if the sensor is connected through the gateway, you can set the poll interval in the gateway settings (for example, once every 30 minutes instead of 5).
• 🔄 Do not reset the sensor unnecessarily - each reset consumes additional energy.
• 🌡️ Avoid extreme temperatures – in the cold below -10°C or heat higher +50°C battery discharges faster.

Average battery life:

• 🔋 LYWSD03MMC: 6-12 months (when connecting through the gateway).
• 🔋 MHO-C401: 12-24 month (due to lack of display).
• 🔋 ClearGrass CGDN1: 8-16 months (depending on the frequency of data transmission).

⚠️ Warning: If the sensor has stopped transmitting data, but the indicator does not blink when you press the button, this is a sure sign of a dead battery. Some users try to "reanimate" the battery with heating or deformation - this is useless and dangerous (risk of explosion.

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Use batteries from well-known brands (like Duracell or Energizer), cheap ones that can leak and damage the sensor contacts.

7. Alternative ways to use the Xiaomi thermometer

In addition to the standard Mi Home connection, Xiaomi thermometers can be used with other systems and even without a smartphone:

1. Connection to Apple HomeKit

Integration with HomeKit will require:

• 📱 Install Home Assistant on iPhone or iPad.
• 🔗 Connect the sensor to the Home Assistant (as described above).
• 🏠 Add Home Assistant as a HomeKit Bridge through the HomeKit Controller plugin.

2. Use without the Internet (local mode)

If you do not have permanent access to the Internet, you can configure local management:

• 🌐 Connect the sensor through the Xiaomi gateway.
• 📱 In Mi Home, disable data transfer to the cloud (in gateway settings).
• 🔄 Use local automation (e.g., Node-RED or Home Assistant).

3. Export of data to Excel/Google Sheets

For temperature and humidity analysis, data can be exported:

1. In Mi Home, open the history of the sensor readings.
2. Click on the export icon (usually in the upper right corner).
3. Choose the format CSV period (for example, the last week).
4. Import the file to Excel or Google Sheets to plot the charts.

⚠️ Note: When exporting data from Mi Home, keep in mind that history is only stored for 30 days. For long-term storage, set up automatic export via Home Assistant or IFTTT.

FAQ: Frequently Asked Questions