How to set autobrightness on Xiaomi: the complete guide

Modern Xiaomi smartphones are equipped with advanced sensors that automatically adjust the level of screen illumination depending on the lighting. However, users often face a situation when this feature works incorrectly: the screen is too dim in the bright sun or, conversely, blinds the eyes in the dark. Understanding how to adjust this setting is critical for comfortable use of the gadget and maintaining eye health.

In this article, we will take a closer look at all aspects of how the light sensor works on MIUI shells and the new HyperOS. You will learn not only about the basic switches, but also about the hidden calibration menus that allow you to “train” the smartphone to respond to light correctly, which is especially true if the company’s standard algorithms seem too aggressive or slow.

A screen that doesn't work properly can have a significant impact on the autonomy of the device. If the system gets it wrong and keeps the backlight at maximum in a dark room, the battery runs out much faster. Let's figure out how to get the display settings to a perfect state without having to get superuser rights.

Basic activation of the function in the settings menu

The first step should always be to check the standard system settings. In most cases, the problem is solved by simply switching the slider, which could accidentally get lost after updating the firmware or resetting the settings, the path to this parameter may vary slightly depending on the version of Android and the shell.

To find the right switch, lower the notification curtain from top to bottom. Find the brightness slider and click on the gear icon or the letter "A" next to it. In the menu that opens, make sure that Auto Brightness is activated. If you use older versions of MIUI, the path may look like Settings → Screen → Brightness Level.

It is important to note that on some Redmi models and POCO s AMOLED-There's an option called Adaptive Brightness, which uses artificial intelligence algorithms to analyze your habits. If you turn on this feature, the phone will remember at what level you are putting the slider in a certain lighting, and next time it will do it itself.

• 🌞 Standard autobrightness responds only to current light sensor readings.
• 🧠 Adaptive brightness is trained based on your manual adjustments in different conditions.
• ⚙️ In Read mode, autobrightness can be ignored to save the set parameters.
• 🔋 Disabling the function often leads to increased battery consumption.

⚠️ Warning: If the screen does not change brightness when the lighting changes after switching on (for example, when getting stuck a flashlight over the top of the housing), it is possible that the sensor is contaminated or blocked by a low-quality protective glass.

Once activated, give the device a few minutes to analyze the environment, and don't expect an instantaneous reaction in the first seconds, as the system averages the readings to avoid flickering the screen when light changes briefly.

Calibration of the light sensor through the engineering menu

If standard methods don't work and the screen is chaotic, you'll need a deeper setup. Xiaomi's smartphones have a hidden CIT (Customer Integration Test) engineering menu designed to diagnose and calibrate hardware components, and this is where you can reset old sensor data and start the recalibration process.

To enter the diagnostic menu, open the Phone app and enter the code ##6484##. The screen will show a list of all the tests. Find the Light Sensor or Light Sensor. In some firmware versions, this section may simply be called Sensor.

Inside the test, you'll see the current luxmeter readings. Close the top of the screen with your palm -- values should drop to almost zero. Remove your hand -- values should rise dramatically. If the numbers don't change, the problem may be physical. If they change, but the autobrightness doesn't work, press Calibration or Start Calibration.

The calibration process usually takes a few seconds, and you may be asked to close the sensor and then open it so that the system records the minimum and maximum thresholds. Once the test is completed, be sure to restart the smartphone so that the new values apply to the system.

Configure through hidden codes and ADB-team

For advanced users who don’t have enough standard tools, there are ways to fine-tune through USB debugging, which allows you to change the sensitivity of the sensor or force the algorithms hidden by the manufacturer for your region.

First, you need to activate the developer mode. Go to Settings. → About the phone and quickly press 7 times on the item "Version" MIUI» (Then, turn on the "Advanced Settings" menu «USB-You'll need a computer with a platform tool installed. ADB.

Connect your phone to your PC and type in a command to check the connection. If it goes well, you can use commands to reset the display settings. For example, a command to reset the screen calibration often looks like cleaning the corresponding section of the settings database, but it is safer to use specialized applications from the Play Market that work through ADB Shizuku.

adb shell settings put system screen_brightness_mode 1

This command enforces automatic brightness control mode at the system level, ignoring some software constraints. 1 means autobrightness, and 0 means manual mode, which can help if the slider in the interface is stuck.

The effect of protective glasses and covers on the operation of the sensor

Often, external factors are the cause of autobrightness malfunctioning. The light sensor on Xiaomi smartphones is usually located at the top of the screen, often hidden under the display or in a narrow frame. If you use a black-edged protective glass or improperly pasted film, they can overlap the sensor.

Check if your security glass is covering the sensor area, and even a microscopic layer of glue or air bubble in that area can distort the readings, making the phone think it's in total darkness, in which case the screen will remain dim even in the bright sun.

Also worth looking at is the case, some massive high-sided protective cases can create shadows on the sensor if you hold your phone in a certain way. Try removing the case and checking the autobrightness in different lighting conditions.

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When sticking a new protective glass, use a template or frame for perfect alignment so as not to close the proximity and light sensor.

Autobrightness problems after MIUI or HyperOS update

Users often complain that after updating the firmware, the autobrightness begins to work worse: it becomes too dim or, conversely, it screens the face. This is due to a change in the algorithms of the display tunnel (display tuning) in new versions of the software. Xiaomi engineers can change the brightness curves to meet new standards or certification.

Newer versions of HyperOS have introduced a feature called “Improving Visibility in Bright Sun,” which can conflict with normal autobrightness. If you notice a sharp spike in backlight, try turning off additional options in the screen menu. Find “Read Mode” or “Eye Safety” and check for their effects.

Sometimes the problem lies in the cache of system services. After a major update, it is recommended to clear the cache of the Settings app and system UI. This can be done through the Settings menu → Apps → All Apps → Find Settings → Clear. Don’t worry, your personal data will not be affected.

⚠️ Warning: Do not install third-party brightness control apps from unreliable sources immediately after a system update.They may conflict with new display drivers and cause cyclical reboots.

If the problem persists for a long time after the update, it makes sense to wait for the patch or roll back to the previous version of the firmware through the Recovery menu, if such an opportunity is provided for your model.

FAQ: Frequently Asked Questions

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Proper calibration of the light sensor through the engineering menu solves 90% of problems with incorrect autobrightness on Xiaomi smartphones.