How to turn off the light sensor on Xiaomi Redmi Note 8

Many owners of the popular Chinese brand smartphones face intrusive screen behavior that changes brightness at the most inopportune moment, especially for the Redmi Note 8, where MIUI algorithms can overreact to changes in lighting, which is not only annoying, but can interfere with comfortable reading or watching video in unstable light conditions.

Users often look for a way to completely deactivate this feature to gain full control of the display backlight. Standard system settings don't always make this obvious, especially after firmware updates. In this article, we'll take a look at all the available methods, including hidden engineering menus and system commands.

A malfunctioning light sensor can also lead to false taps while talking or using messengers. So understanding how to operate this module is an important skill for any Xiaomi user. We will look at both the software and hardware aspects of this component.

Why Users Need to Turn Off Auto Brightness

The main reason Redmi Note 8 owners are keen to turn off automatic adjustment is because of the unpredictability of screen behavior. calibration algorithms are often mistaken, making the screen too dim in bright sun or excessively bright in a dark room.This not only reduces comfort, but also affects the battery life of the device.

And there are specific use cases where constant brightness changes are highly undesirable, such as when using a smartphone as a navigator in a car or when reading books in changing lighting, where manual control becomes a priority.

Another important aspect is the touchscreen problem: the proximity and light sensor located at the top of the screen can conflict with the protective glass or film, which causes the screen to go out during a conversation or video call if the finger accidentally overlaps the sensor area.

⚠️ Warning: Disabling the sensor completely through system files can cause the screen to stop fading during a conversation, increasing the risk of accidental cheek pressing.

Some users have noted that after turning off the autobrightness function, the battery starts to discharge more slowly, which is logical, since the system stops constantly polling the sensor and adjusting the backlight voltage. However, if you are used to maximum brightness, the savings can be small.

Standard method through system settings

The simplest and safest method of brightness control is built into the standard MIUI settings menu. It does not require superuser rights or third-party software installation. However, in the latest versions of the shell, this item can be hidden or renamed by developers to "improve the user experience."

First, you need to unlock your smartphone screen and go to the main menu, and find the gear icon, which is the input to the system settings, and this is where all the major controls of the device, including the display, are concentrated.

In the list that opens, look for a Screen or Display section, and depending on the firmware version and region, the name may vary slightly, and inside that menu, there's a brightness slider and a switch that's responsible for automatic adjustment.

• 🔍 Open the settings on the desktop.
• 📱 Go to the Screen (or Display) section).
• 🌗 Find the brightness level and turn off the tumbler Autosetting.
• ✅ Set the brightness slider to a comfortable level for you manually.

If the brightness still jumps after doing these actions, it may be that the system activates adaptive read or energy saving mode, and check the settings in the Battery section as some energy saving profiles force their lighting control algorithms to be enabled.

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Standard shutdown via settings is the safest method that doesn’t require special knowledge, but it may not work on some versions of MIUI with sleepy autobrightness.

Use of the CIT Engineering Menu

For deeper diagnosis and control of hardware components in Xiaomi smartphones, there is a special engineering menu known as CIT (Customer Integration Test), through which you can check the performance of the sensor and, in some cases, change its behavior.

To get into this menu, open the phone's standard app (caller) and type the combination ##6484##. If the code is entered correctly, the system will automatically run the test interface without having to press the call button. Here is a list of all the tests available.

In the test list, look for a item that's associated with the Light Sensor or the Proximity Sensor, and if you click on it, you'll see the current readings of the sensor in real time, and if you palm over the top of the screen, you'll see the change in the digital values, and that will help you see if the module itself is working.

Code for logging into the engineering menu: ##6484##


Alternative code: ##4636##

While it is often impossible for ordinary users to directly disable the sensor from here, this tool is critical for diagnostics. If the sensor shows zero values or maximum values in this menu when the camera is closed, the problem can be hardware.

Configure with ADB and system commands

For advanced users who want to gain full control of the system, there is a method of disabling the sensor through USB debugging. This method requires connecting the smartphone to the computer and installing ADB drivers (Android Debug Bridge), which allows you to make changes to system tables that are not available through a regular interface.

Before starting the procedure, you need to activate the developer mode. To do this, quickly click on the build number in the About Phone section seven times. After the "You have become a developer" notification appears, a new option will appear in the settings menu Additional or Advanced Settings.

Turn on USB Debugging and connect your phone to your PC. You'll see a request for debugging permission on your smartphone screen, confirm it, and you can send commands from your computer to change the system's global settings.

• 💻 Connect the Redmi Note 8 to your computer via the original cable.
• 🔧 Enter the command to turn off autobrightness: adb shell settings put system screen_brightness_mode 0.
• 🔄 To return autoset, use the value 1: adb shell settings put system screen_brightness_mode 1.
• 📉 For manual setting of brightness level (0-255): adb shell settings put system screen_brightness 120.

This method is effective when MIUI software bugs ignore manual settings, the team force the brightness mode to a static value, ignoring the light sensor readings, but after the device is restarted, the settings can reset if they are not fixed in the system.

⚠️ Attention: Use ADB-Introducing incorrect commands can lead to unstable system operation or cyclical reboot.

Third-party applications for brightness control

If the system methods seem too complex or inefficient, applications from the Google Play Store come to the rescue. There are many utilities that intercept the brightness control and block the system from changing it automatically, and they create a control layer on top of the system.

One popular solution is the Screen Brightness Controller app, or analogues, which, once installed, asks for permission to display over other windows and access system settings, and allows you to create a profile that captures the backlight level rigidly.

The advantage of this approach is flexibility: you can set different profiles for different applications or times of day, for example, during the day the brightness can be high, and in the evening it can be minimal, but always manual, this bypasses the restrictions imposed by the MIUI shell.

Keep in mind that a third-party application can consume additional battery power in the background, and some antiviruses or MIUI systems may try to kill the process to save energy, so add the application to the exceptions.

Table of comparison of disconnection methods

To make it easier for you to choose the right method, we have prepared a comparison table that will help you assess the risks and complexity of each method for your particular situation.

Possible problems and solutions

When you turn off the sensor, you may encounter a number of challenges, such as when you update the firmware, the settings can fly off, or the system will force you to return autobrightness, a Xiaomi security mechanism designed to prevent the matrix from burning out or the screen from getting too dim.

If the screen gets too dim even at its maximum after manipulation, you may have touched the calibration factors, in which case resetting the screen settings or completely resetting the device to factory settings will help. Remember to back up the data before radical actions.

Also (a common problem) is that the sensor is physically broken, and if it's stuck and it's always dark, the screen will always be dim, and then the software won't help, so you'll need to replace the plume or the module at the service center.

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Before going to the service center, try gently wipe the top of the screen with an alcohol napkin - often the speaker's pollution blocks the light sensor.

Sometimes it helps to update the display drivers through the Recovery menu if you use custom firmware, but for stock users, waiting for an official patch from the MIUI developers is the best solution.

Frequently Asked Questions (FAQ)