Approximation sensor Xiaomi Redmi Note 8 Pro: settings and calibration

Owners of the smartphone Xiaomi Redmi Note 8 Pro often face a situation when the screen does not go out during a conversation or, conversely, is blocked without the ability to answer a call. The cause of such failures is often incorrect operation of the sensor responsible for determining the distance to the user's face.

The problem is that the standard MIUI menu doesn’t have a separate switch called the Approximation Sensor that can be turned off or turned on. Calibration and control of this component is hidden in special engineering sections or requires certain sequences of actions. Understanding the architecture of Android on Xiaomi devices helps to find a solution faster.

In this article, we will detail where the sensor is physically and programmatically located, how to fine-tune it through a hidden menu, and what to do if software methods don't help. The physical sensor on the Redmi Note 8 Pro is located at the top of the display, hidden under a security glass next to the speaker. The absence of a visible hole does not mean the lack of technology.

Location and operation of the sensor

The Proximity Sensor technology in the Redmi Note 8 Pro is infrared, it emits invisible light and analyzes its reflection from objects. If the reflected signal returns quickly, the system blocks the touchscreen, preventing accidental cheekstrokes, a critical element of smartphone ergonomics.

Physically, the module is in the upper center of the front panel. Unlike the older models, there is no separate transparent window, because it uses hidden placement technology under the display. Any contamination, greasy spots or improperly pasted protective film can distort the sensor readings, causing false positives.

So, software processing is real-time, and if you notice that the screen goes out when you're just holding the phone in your hand, or when you're talking, the thresholds are not working properly, and you often need to have a forced calibration to reset the reference distances.

⚠️ Warning: Before any manipulations begin, wipe the top of the screen carefully, often solved by simply cleaning the glass of contaminants that block the infrared beam.

Diagnostics through the Engineering Menu

To verify the component’s performance accurately, MIUI has a built-in diagnostic tool that allows you to see raw data from the sensor without installing third-party applications, accessed through universal code that runs on most Xiaomi devices.

You need to open the standard Phone app and enter the combination ##6484##. Once you enter the last star, the CIT (Customer Interface Test) menu will automatically open.

In the window that opens, you'll see the numerical values. When there's nothing in the way of the sensor, the value should be close to zero or minimal. If you put your palm to the top of the screen, the readings should change. If the numbers jump or don't respond to your hand, the problem may be hardware.

Using the engineering menu is safe for user data, but don't change the values in other parts of the test without understanding the purpose of the test, a tool designed by engineers to quickly diagnose the hardware component.

Sensor calibration procedure

If the diagnostics show that the sensor is responding but not doing it correctly, you need to calibrate. In some versions of the Redmi Note 8 Pro firmware, this feature is available directly from the CIT menu.

Type ##64663## on your phone keyboard. In the list that opens, select "Proximity sensor." Follow the instructions on the screen: You usually need to remove your hand from the screen, press "Calibration," and then close the sensor with your hand and press the confirmation button again.

The process takes no more than a minute. Successful calibration is confirmed by the message "Pass" or "Success", after which the phone is recommended to restart, so that the new parameters are stored in the memory of the controller.

It is important to perform the procedure in good light, but without direct sunlight falling on the screen. Bright light can interfere with the infrared radiation of the sensor, which will lead to incorrect calibration.

Hidden settings in the developer menu

In the shell. MIUI There are additional options that can affect how sensors work. To access them, you need to activate the developer mode. → On the phone and press quickly 7-10 once under the heading “Version” MIUI".

Once activated, the "Additional" menu will have a "Developers" section, and you should look for sensor-related options here, but it's worth noting that direct sensitivity adjustments to the Proximity Sensor are rare here, and most often you can reset calibration settings or check status.

In some cases, the "Raise Phone to Activate the Screen" option, which uses the same sensors, helps to disable: Settings → Lock screen → Pocket mode. Turning off "in your pocket" sometimes solves the problem of false locks.

Experiment with these settings carefully. Changing the parameters of the "in the pocket" mode is the most effective software method for combating sensor hypersensitivity.

Third-party management applications

If Xiaomi's system tools don't work, you can turn to tools from the Google Play Store. There are many tools, such as "Proximity Sensor Reset & Fix" or "Sensor Test for Android", which allow you to conduct a deeper diagnosis.

Applications can force the sensor driver to reset or offer an alternative calibration algorithm, and some can completely programmatically turn off the sensor if you're willing to put up with the screen not going to go out in the ear (button control).

However, installing third-party software requires permissions to access the system. Be careful when choosing an application: read reviews and check access rights. Not all programs are equally useful and safe for Redmi Note 3 Pro and later.

⚠️ Note: Using applications with Root rights or deep access to the system can cause other modules to fail.

Hardware causes of malfunctions

When software methods, calibration and resetting don't work, there's a high probability of physical failure. In the Redmi Note 8 Pro, the proximity sensor plume is often integrated into the overall front camera plume and speaker. Damage to any part of the plume affects all components.

A common cause is moisture, and even if the phone hasn't sunk, high humidity or condensate can oxidize the sensor contacts, requiring disassembly of the device and cleaning of the contacts with alcohol or replacement of the module.

It's also worth checking the integrity of the protective glass, because if it cracked at the top, the optical properties could change, and the sensor stopped "seeing" reflected light correctly, and replacing the glass often solves the problem without replacing the sensor itself.

Diagnostics of hardware requires electronics skills, and if you're not confident in your abilities, it's best to contact a service center, especially if the phone is warranty-free.

Resetting settings as a last resort

If nothing works, the radical method is a complete factory reset, which will delete all user data, so be sure to back up your contacts, photos and apps.

Pathway to reset: Settings → Phone → Settings Reset → Erase all data. Once rebooted, the phone will look like new. If the sensor is not working properly in the clean state of the system, the diagnosis is unequivocal: hardware failure.

Often users forget that conflicting apps installed recently can cause problems. Before a complete reset, try running your phone in Safe Mode. If the sensor is working perfectly in Safe Mode, look for the culprit among the installed apps.

💡

Before a full reset, try simply restarting your phone in safe mode (press the off button, then keep the "off" option on the screen for a long time) to help you understand whether the third-party application is to blame.

Frequently Asked Questions (FAQ)

💡

In most cases (90%) the problem is solved by correct calibration through the engineering menu or by replacing the poor quality protective glass.