How autobrightness works on Xiaomi Redmi Note 8 Pro: technical nuances and hidden settings

Xiaomi Redmi Note 8 Pro is one of the most popular mid-range smartphones, Released in 2019, but still relevant thanks to the powerful MediaTek Helio processor. G90T and AMOLED-One of the key features that affect usability and autonomy is automatic brightness control. But how does it work? Why does the screen sometimes seem too dim or blind? In this article, we will understand the technical details, algorithms. MIUI and hidden customization possibilities.

Many users mistakenly believe that autobrightness is just a reaction to light. In fact, the Redmi Note 8 Pro uses a comprehensive mechanism that takes into account not only the data from the light sensor, but also the user's behavioral patterns, screen temperature, and in recent versions of MIUI - even the color temperature of the ambient light, while Xiaomi's algorithms are different from standard Android solutions, which is not always obvious.

If you’ve ever wondered why avtobrightness is delayed or can you calibrate the sensor manually?, this article will provide exhaustive answers. We’ll also reveal a unique feature of the Redmi Note 8 Pro: in this model, autobrightness is tied to the processor, which affects the smoothness of adjustment at high loads.

Technical basis: sensors and hardware components

The ambient light sensor is at the top of the screen next to the front camera. The Redmi Note 8 Pro uses Broadcom’s APDS-9960 model, the same chip as the 2019-2020 flagships, and can measure light intensity ranging from 0.01 lux (total darkness) to 10,000 lux (direct sunlight).

The sensor has a spectral sensitivity close to the human eye, and it not only captures the overall illumination, but also analyzes the proportion of the blue and red spectrum, allowing MIUI to adjust not only the brightness but also the color temperature of the screen (Read 2.0 in the display settings), for example, when the incandescent lamp is warm, the screen automatically shifts to a yellow hue.

In addition to the light sensor, the following are involved in the brightness adjustment:

• 🔹 Gyroscope and accelerometer: determine the angle of the screen (for example, when using a smartphone lying down, the brightness can automatically decrease).
• 🔹 Approximation Sensor: Turns off the backlight when you bring your phone to your ear during a call.
• 🔹 Thermometer: when the screen overheats (above 45)°C) the brightness is forced to decrease to protect the matrix.
• 🔹 MediaTek Helio processor G90T: It processes data from sensors and uses algorithms. MIUI real-time.

⚠️ Note: In the Redmi Note 8 Pro, the light sensor has no physical protection from dust. If you notice that the autobrightness has become incorrect (for example, in the dark the screen remains bright), check the cleanliness of the upper panel of the screen - dust or greasy prints can distort the readings.

MIUI Algorithms: How Smartphones “Learn” Your Habits

Unlike Android, which uses a fixed curve for autobrightness (luminance-to-lux) in its bare-bones, MIUI has an adaptive algorithm that consists of three layers:

1. Basic level: standard brightness curve laid by Xiaomi (similar to Android AOSP, but with corrections for AMOLED-matrixes).
2. Behavioral layer: MIUI analyzes how you manually adjust brightness in different conditions, and adjusts the curve to your preferences, for example, if you constantly add brightness in sunny weather, the system will remember this.
3. Context Layer: Takes into account the active application (in games or cameras, the brightness can automatically increase), the battery level and even the time of day.

Fun fact: In the Redmi Note 8 Pro, the autobrightness algorithm is tied to performance mode, so if the battery settings are power saving, the brightness curve shifts toward darker values, even with sufficient light, which is designed to extend autonomy, but can cause discomfort.

MIUI also uses machine learning to predict brightness, for example, if you drop your brightness to 30 percent every night at 22:00, the system will automatically do that in a few days, stored in /data/system/autobrightness.xml and reset before-hard reset.

Where to hide the settings of autobrightness in MIUI

Most users are limited to turning on/off the autobrightness in the notification curtain, but the Redmi Note 8 Pro has hidden options to fine-tune the behavior of the feature.

Settings → Display → Brightness → Automatic brightness adjustment

However, only basic options are available here. Advanced customization requires:

1. Activate Developer Mode (7 times click on the MIUI version in About Phone).
2. Go to Settings → Additional → For developers → Autobrightness.
3. Enable Adaptive Brightness (if disabled) and adjust the Sensor Sensitivity slider.

The developer menu is also available:

• 🔧 Minimum brightness – sets a lower threshold (useful for use in total darkness).
• 🔧 Color temperature correction – allows you to turn off automatic tweaking of shades.
• 🔧 Log of the light sensor – shows the current values in the luxes (useful for diagnosis).

Include adaptive brightness in the developer menu|Determine the sensitivity of the sensor 70-80%|Turn off color temperature correction if the screen appears yellowish|Check the minimum brightness (recommended) 5-10%)|Reboot your phone after the changes-->

Why the lighting is not working properly: typical problems

Despite the advanced algorithms, Redmi Note 8 Pro users often encounter autobrightness bugs.

Particularly noteworthy is the problem of "hanging" brightness after the MIUI update, which is due to the fact that new firmware versions can reset custom brightness curves.

1. Turn off and re-energize the autobrightness.
2. Manually adjust the brightness in different lighting conditions (MIUI will retrain in 1-2 days).
3. Reset the settings via the engineering menu (code above).

⚠️ If after resetting the autobrightness settings through the engineering menu, the screen became too dark, do not panic - this is temporary. MIUI It takes a day to collect new light data, and you can use manual adjustments during this time.

How to Calibrate Auto Brightness Manually (without Root)

MIUI allows you to train the autobrightness algorithm to your preferences without using root rights.

1. Turn off the autobrightness in the notification curtain.
2. For 2-3 days, adjust the brightness manually in different conditions: 🌞 Outside in the bright sun. 🏠 In a room with artificial lighting. 🌙 Total darkness before bedtime.

Turn the autobrightness back on. MIUI will analyze your actions and adjust the curve.

For more accurate calibration, you can use the engineering menu:

1. Enter the code ##36446337##.
2. Go to the Light Sensor section.
3. Press Do Calibration and follow the instructions (you will need to point the phone at the light source and then into darkness).

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If you care about autonomy, but autobrightness is unpredictable, try Google Play's Lux Auto Brightness app, which allows you to create your own brightness curves and is more stable than the standard MIUI solution.

Comparison with other Xiaomi smartphones: what has changed in the new models

The autobrightness algorithms in the Redmi Note 8 Pro are inherited from the Mi 9T Pro, but with some simplifications. For example, Xiaomi flagships (starting with the Mi 10) use a dual light sensor for more accurate measurements, while the Redmi Note 8 Pro uses a single one, leading to the following differences:

The Redmi Note 8 Pro’s main advantage over newer budget models (like the Redmi Note 10) is that it supports hardware color temperature correction, which is software-based on cheap smartphones, which causes color distortions when brightness changes.

However, flagships (such as the Xiaomi 12 Pro) have a dynamic refresh rate that works in tandem with autobrightness. The Redmi Note 8 Pro has a fixed frequency (60 Hz), which simplifies algorithms but lacks flexibility.

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If you are planning to switch to a new Xiaomi model, consider that in smartphones on Snapdragon (for example, the smartphone is not a smartphone, POCO X3 Pro) Autobrightness can be smoother by optimizing drivers better. AMOLED-The screens in the Redmi Note 8 Pro provide a deeper black color at low brightness, which compensates for some drawbacks.

FAQ: Frequent questions about autobrightness on the Redmi Note 8 Pro