How to calibrate the light sensor on Xiaomi: detailed instructions with nuances

The light sensor in Xiaomi, Redmi and POCO smartphones is responsible for automatically adjusting the brightness of the screen, adapting color temperature and even activating certain functions (for example, reading mode or night filter). However, over time, its work can get lost: the screen becomes too dark in normal lighting, the brightness jumps for no reason, or the sensor stops responding altogether, the reasons lie in sensor contamination, software failures or incorrect settings of the system.

In this article, you will find 3 proven calibration methods, from simple actions in the settings menu to hidden engineering commands. We will also discuss how to diagnose a sensor malfunction when calibration does not help, and what to do if the problem returns after the MIUI update. The instructions are relevant for all modern models, including the Xiaomi 14, Redmi Note 13 Pro+ and POCO F6, but taking into account the features of different versions of the firmware.

Signs of incorrect operation of the light sensor

Before you start calibrating, make sure the problem is really sensor-related.

• 🌓 The screen spontaneously dims to a minimum even in bright light (for example, outside during the day).
• 🔦 Brightness jumps for no apparent reason - it increases, then falls in the same room.
• 🌃 Night mode is turned on at inappropriate times (for example, at 16:00) or does not turn off in the morning.
• 📱 In brightness settings, the autoregulatory slider is inactive or it is gray in color.
• 🚫 Forced autobrightness shutdown doesn’t solve the problem – the screen remains too dark/bright.

If any of these signs are present, the sensor needs to be calibrated, but there are also false positives: for example, some applications (such as TikTok or dynamically backlit games) can cause spikes in brightness. To rule out their effects, check the screen behavior on a clean desktop or in safe mode.

⚠️ Attention: On models with AMOLED-screens (for example, Xiaomi 13 Ultra or Redmi) K70 Pro) the light sensor may conflict with the function DC-Before calibrating, turn it off in Settings. → Display. → Additionally. → DC-dimming.

Calibration Preparation: What to Do in Advance

Calibration of the sensor is a simple process, but it requires preparation, and neglecting these steps can lead to incorrect results or even make things worse.

1. Clean the sensor. The light sensor is usually located next to the front camera (at the top of the screen). Wipe it with a soft lilac-free napkin soaked in alcohol. Do not use wet wipes or rough fabrics!
2. Update your firmware. Go to Settings → About Phone → Update MIUI and install the latest version. In some updates, Xiaomi fixes autobrightness bugs.
3. Reset the display settings. This will remove custom brightness profiles: Settings → Display → Additional → Reset the display settings.
4. Charge the phone. The battery level should be at least 50% - at low charge, the system can limit the functionality of the sensors.

If the problem has disappeared after cleaning the sensor, you don't need calibration. Otherwise, move on to the following methods. Note that on some models (for example, the POCO X6 Pro), the light sensor is combined with the proximity sensor, and if after calibration, the gestures during the call stop working (for example, turning off the screen when you touch the ear), you will need to reconfigure.

Method 1: Calibration through the engineering menu (for advanced users)

This method is the most accurate, but it requires caution: improper actions in the engineering menu can disrupt other sensors, and the instructions are suitable for all smartphones on MIUI 12-14 and HyperOS.

Steps to enter the engineering menu:

1. Open the Phone app and type the combination: ##6484## (some models run ##36446337##).
2. Select the Ambient Light Sensor.
3. Press Calibrate and follow the instructions on the screen, and you usually need to take your phone one by one to a bright light source and then place it in a dark place.
4. Once completed, restart the device.

If the combination does not work, try an alternative method:

1. Install the MTK Engineering Mode (for MediaTek processors) or Qualcomm Engineer Mode (for Snapdragon).


2. Run it and select Hardware Testing → Ambient Light Sensor.




3. Press Auto Test and wait until it is completed.

⚠️ Note: Some models (e.g. Xiaomi) 12T or Redmi Note 12 Pro) the engineering menu may be blocked, in which case use Method 2 or Method 3.

Method 2: Calibration through MIUI settings (without root)

The safest method, which doesn't require any special knowledge, is suitable for most users, and the idea is to reset the adaptive brightness settings and retrain the system.

Instructions:

1. Go to Settings → Display → Brightness.
2. Turn off the Auto Brightness slider (if it is active).
3. Manually set the brightness to 50% and wait 10 seconds.
4. Turn back on Auto Brightness and move the slider to the far left (0%), then to the right (100%), and again to 50%.
5. Turn off the screen for 30 seconds, then unlock the phone.

Then the system will start retraining the sensor to speed up the process.

• 💡 Alternately place your phone in a dark place (such as a desk drawer) and under bright light (such as a desk lamp).
• 📱 Repeat the action 3-5 times, giving the phone 5-10 seconds to adapt in each state.
• 🔄 Reset the device.

This method works on 80% of models, but may require a repeat after 1-2 days if the sensor is badly “off”. On the POCO F5 and Redmi K60, you sometimes need to reset the adaptive color temperature settings in Settings → Display → Color Mode.

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If the screen is still too dark after calibration, try increasing the minimum brightness threshold, manually adjust the brightness to a comfortable level with the auto-adjustment turned off, then activate it again, and the system will remember your preferences.

Method 3: Calibration through ADB (for power users)

If the engineering menu is not available, and the standard calibration did not help, you can use the ADB-This method requires a computer and enabled debugging. USB, It gives you a deeper control over the sensor.

Step-by-step:

1. Turn on Developer Mode: Go to Settings → About Phone and click on MIUI Version 7 times.
2. Activate debugging over USB in Settings → Additional → For developers.
3. Connect your phone to your PC, install it. ADB-Drivers and open the command line in the folder with the platform-tools.
4. Enter the commands alternately: adb shell su echo 1 > /sys/class/sensors/light/calibration If root is requested but not, use the alternative command: adb shell settings put system. screen_brightness_mode 1
5. Reboot the phone.

To reset the calibration to factory settings, use:

adb shell settings delete system screen_auto_brightness_adj

⚠️ Note: Xiaomi with Snapdragon processors 8 Gen 2/3 (for example, Xiaomi 14 Pro) ADB-The commands to calibrate the sensor may not work because of the manufacturer's limitations. 1 service-seeking.

Table: Compatibility of calibration methods with popular models

On HyperOS models (e.g. Xiaomi 14) after calibration, additional adjustment of adaptive backlight may be required in Settings → Display → Adaptive Brightness → Brightness Training.

What if calibration doesn’t help?

If the light sensor is not working properly after all the manipulations, the problem may be hardware or software.

• 🛠️ Sensor damage: Physical malfunction (for example, after a fall or moisture) requires a replacement of the sensor. The cost of repair in the service center Xiaomi — from 1,500 to 3,000 rubles.
• 📱 On custom firmware (like LineageOS or Pixel Experience), the sensor may not work. MIUI.
• 🔄 Failure after the update. If the problem occurred after the update, roll back to the previous version of the firmware via Fastboot or wait for a patch.
• 🧹 Sorting the connector. Dust or oxidation of the contacts on the sensor plume can disrupt the sensor's operation. Solution is disassembly and cleaning (requires experience).

To diagnose hardware problems, use the sensor test:

1. Install the Sensor Test app (such as Innovell’s Sensor Test).
2. Run the Light Sensor test.
3. Point the light of the flashlight at the sensor - the values should vary from 0-10 lux (darkness) to 10,000-50,000 lux (bright light).

If the readings are unchanged or zero, the sensor is faulty. If the values jump randomly, the problem is the software calibration (repeat Method 1 or 3).

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Before visiting the service center, make a backup copy of the data - during the diagnosis, it may be necessary to reset the phone to factory settings.

FAQ: Frequent questions about calibration of the light sensor