How to set up Xiaomi hygrometer: connection, calibration and fine settings

Xiaomi Hygrometers are some of the most popular microclimate monitoring devices in your home, greenhouse or office, they are compact, accurate (when set up correctly) and easily integrated into the Mi Home ecosystem. However, many users face problems: the device does not connect to the network, shows incorrect data or suddenly shuts down. In this article, we will analyze all the stages of settings, from the first on to fine calibration, and also explain how to avoid typical errors.

Feature of Xiaomi hygrometers (for example, models MiJia Bluetooth Temperature and Humidity Sensor 2 or ClearGrass) CGDK2) They are based on Bluetooth Low Energy protocol (BLE). This means that not only a smartphone is needed to work smoothly, but a Xiaomi gateway (such as the Mi Smart Home Gateway) or other hub device, and without it, the data will only be updated when the Mi Home app is open, which is inconvenient. We will explain in detail how to configure the hygrometer bundle with the gateway and why it is important.

If you've tried to adjust the hygrometer but it's "not visible" in the app or shows absurd values (for example, humidity is 99% in a dry room), do not rush to return the device to the store. In 80% of cases, the problem is solved by correct calibration or resetting settings. Next, step-by-step instructions for different scenarios.

1. Preparation for setting up: what will be needed

Before you start connecting, check if you have everything you need, and without some components, the hygrometer will either not work or will function with restrictions.

• 📱 Android smartphone (version 6.0)+) or iOS (10.0)+) with Mi Home installed (you can download it from Google Play or App Store).
• 🔋 Lock charger (if used) or batteries CR2032 for hygrometer (usually come with a set, but it is better to have spare ones).
• 🌐 Stable Internet connection (Wi-Fi 2.4 GHz) to set up the gateway. Hygrometer itself to Wi-Fi does not connect to the Wi-Fi!
• 🔄 Xiaomi Gateway (optional, but highly recommended for automatic data collection) Suitable models: Mi Smart Home Gateway 3, Aqara Hub M2 Mi Gateway Zigbee 3.0.

If you do not have a gateway, the hygrometer will work in a limited mode: the data will only be updated when the Mi Home application is open within Bluetooth range (up to 10 meters).

⚠️ Note: Xiaomi hygrometers are not compatible with Wi-Fi routers that only work in the 5 GHz band. To configure the gateway, you need a router with support for 2.4 GHz.

2. Connecting the hygrometer to the Mi Home application

The process of connecting the hygrometer to the smartphone takes no more than 5 minutes, if you follow the instructions, the main thing is not to miss the activation step of Bluetooth on the phone.

Open the Mi Home app and follow the following steps:

1. Press the badge "+" (Add the device) in the upper right corner.
2. Select the category "Sensors" → "Temperature and humidity".
3. Make sure the hygrometer flashes a blue light (if not, remove and insert the battery back).
4. Click "Connect" and wait for the app to find the device.
5. Select a room where the hygrometer will be located (for example, "Bedroom" or "Children's").
6. Confirm the device's addition.

If the hygrometer is not located, check:

• 🔵 Is Bluetooth enabled on your smartphone.
• 📱 Distance between phone and hygrometer (should be no more than 5 meters).
• 🔋 Battery charge (if the indicator does not flash, replace the battery).
• 📲 Mi Home version of the app (update to the latest in the app store).

Once successfully connected, the app will have a tile with current temperature and humidity readings, but this data may be inaccurate – calibration is required to work properly.

3. Hygrometer calibration: why it is important and how to do it

Xiaomi’s new hygrometers often show inflated or understated humidity due to production features. 60-70%, though the actual — 40-50%. This is not a marriage, but a sensor error that can be adjusted.

Calibration will require a reference hygrometer (e.g., a mechanical Bimex or an electronic Xiaomi VeSync) or a salt test. We will look at both methods.

Method 1: Calibration by reference hygrometer

1. Place both hygrometers (reference and Xiaomi) next to each other 12-24 one-room.
2. Compare the readings. For example, if the reference is 45 percent and Xiaomi is 55 percent, the difference is +10%.
3. In the Mi Home app, go to the hygrometer settings → "Sizing" → specify the amendment (-10% in our example).

Method 2: Salt test (if there is no reference hygrometer)

This method allows you to create an environment with a fixed humidity of 75%:

1. Take a sealed container (such as a plastic box with a lid).
2. Put salt on the bottom with a layer of salt 1-2 Add some water to make the salt wet but not completely dissolve.
3. Place the hygrometer in the container, close the lid and leave on 6-8 hours.
4. If the hygrometer is not 75%, calibrate it manually through the app.

⚠️ Warning: Don't use iodized salt or sugar for the test, they'll give the wrong result. Only pure table salt (NaCl) creates exactly 75 humidity%.

After calibration, restart the hygrometer (remove and insert the battery). 10-15 minutes, they should be stabilized.

💡

If the hygrometer is lying after calibration, try resetting it to factory settings, holding the button on the back panel (if any) for 10 seconds or removing the battery for 5 minutes.

4. Connecting the hygrometer to the Xiaomi gateway for automatic monitoring

Without a gateway, the hygrometer will only send data when the Mi Home app is open, and to receive notifications and see the history of changes in real time, you need to link it to the gateway.

1. Make sure that the Xiaomi gateway is already added to the Mi Home and connected to Wi-Fi.
2. Open the hygrometer settings in the application → "Additional settings" → "Connect to the lock".
3. Select your gateway from the list (e.g. Mi Smart Home Gateway 3).
4. Wait for synchronization (can take up to 1 minute).

After connection:

• 📊 The data will be updated every time 5-10 minutes (depending on the model of the gateway).
• 🔔 You can adjust the notifications when the humidity is outside the normal range (for example, if the humidity drops below 30% or rises above 70%).
• 🌍 The testimonials will be available at Mi Home even if you are far from home.

If the gateway doesn't see the hygrometer:

• 🔄 Reboot the gateway (turn off power for 30 seconds).
• 📱 Update the gateway firmware in the Mi Home settings.
• 📡 Check that the hygrometer is within the range of the gateway (up to 10 meters without obstacles).

5. Set up notifications and automations

One of the key functions of the hygrometer is to alert you to critical changes in the microclimate, for example, if the humidity in the nursery has dropped below 40%, it can cause discomfort in the child, set up notifications and automate.

How to set up notifications:

1. In the Mi Home app, open the hygrometer settings.
2. Select "Notifications" → "Add a rule".
3. Specify a condition, for example: “Humidity < 40%" or "Temperature > 28°C".
4. Select the action: "Send notification" or "Enable another device" (for example, humidifier).

Examples of useful automation:

To set up automation, go to Automation in Mi Home and create a new script. Select the hygrometer as the trigger, and then specify the device or action that should trigger.

⚠️ Note: If you have multiple hygrometers in different rooms, adjust the notifications separately for each (50-70%) will be excessive for the bedroom (40-60%).

6 Problems and Solutions: What to Do If the Hygrometer Does Not Work

Even when properly adjusted, the hygrometer can be unstable, and let's look at the most common problems and how to fix them.

Problem 1: Hygrometer is not connected to the application

• 🔋 Check the battery (it should be) CR2032 3V).
• 📱 Update Mi Home to the latest version.
• 🔄 Reboot your smartphone.
• 📡 Make sure there are no interference sources nearby (microwaves, other Bluetooth devices).

Problem 2: Temperature or humidity readings do not change

• 🕒 Wait. 10-15 The sensor needs time to stabilize.
• 🔄 Remove and insert the battery back.
• 📊 Check if the calibration settings are wrong.
• 🌡️ If the hygrometer was in extreme conditions (for example, in the cold), let it heat up to room temperature.

Problem 3: Hygrometer disconnects from the gateway

• 📡 Check the distance between the hygrometer and the gateway (maximum 10 meters without walls).
• 🔌 Reboot the gateway (turn off power for 1 minute).
• 📋 Update the gateway firmware in the Mi Home settings.
• 🔄 Remove the hygrometer from the app and add it again.

If the Xiaomi MiJia Bluetooth Temperature and Humidity Sensor 2 hygrometer continues to show a humidity of 99% in a dry room after all the manipulations, the sensor is most likely defective. In this case, contact the service center - such devices are subject to replacement under warranty.

7.Integration with other smart home systems

Xiaomi hygrometers can be connected not only to Mi Home, but also to other platforms, such as Home Assistant, Google Home or Apple HomeKit (using bridges), which expands the possibilities of automation.

Connecting to Home Assistant

For integration, you will need:

1. Install Home Assistant on a Raspberry Pi or other server.
2. Add the Xiaomi Miio component via configuration.yaml:

sensor:


- platform: xiaomi_mijia




mac:'XX:XX:XX:XX:XX:XX'#MAC- address of hygrometer




temperature_sensor: true




humidity_sensor: true




bindkey:'YOUR_BIND_KEY' #Box Key (can be obtained via Mi Home)

1. Reboot Home Assistant.

Connecting to Google Home

This is a cloud bridge, such as the Mi Home Skill.

1. In the Google Home app, click "Add" →"Set up the device".
2. Choose "More options" → "Mi Home".
3. Log in to your Xiaomi account and allow access.
4. The hygrometer will appear in the list of Google Home devices.

After integration, you can control the voice hygrometer through Google Assistant or Alice (if you connect to Yandex Smart Home).

💡

For stable operation of the hygrometer in third-party systems (Home Assistant, Google Home), be sure to use the Xiaomi gateway. Without it, the data will only be updated when the Mi Home is open.

8. Tips for placing a hygrometer for accurate readings

Even the most accurate hygrometer will lie if it's placed incorrectly.

• 🚫 Do not place the hygrometer next to:
• ✅ The best seats:

If you use a hygrometer to monitor a greenhouse, place it at a height. 50-70 In the nursery, it's better to hang the sensor on the wall at a distance. 1-2 crib-foot.

Remember, the temperature and humidity can vary greatly even in the adjacent rooms, for example, in the kitchen, the humidity is often higher due to cooking, and in the bedroom, lower due to the operation of the air conditioner. If you want accurate data, install hygrometers in each key area.

FAQ: Frequent questions about Xiaomi hygrometers