How to turn on the proximity sensor on Xiaomi Redmi Note 8 Pro: a complete guide with verification and configuration

The proximity sensor in the Xiaomi Redmi Note 8 Pro is a small but critical element that automatically shuts down the screen during phone calls. When you hold your smartphone to your ear, the sensor registers the obstacle and extinguishes the display, preventing accidental pressing and saving battery power, but many users face a situation where this sensor suddenly stops working — the screen does not go out when you call, or, conversely, it turns off for no reason.

In this article, we will not only examine the standard way to turn on the proximity sensor through the MIUI settings, but also alternative activation methods, fault diagnosis, and hidden functions that are not written about in the official instructions, pay special attention to the typical errors that users make when setting up, and give a checklist for quick checks of the sensor’s health.

If your Redmi Note 8 Pro is not behaving properly during calls — the screen is not responding to the approach or the sensor is delayed — this guide will help to get everything back to normal without going to the service center. And for those who like to dig deeper, we will reveal a few technical nuances related to the operation of the infrared sensor and its interaction with the firmware.

What is the proximity sensor and how it works in the Redmi Note 8 Pro

The proximity sensor in the Xiaomi Redmi Note 8 Pro is a compact module located at the top of the screen next to the front camera. Its main task is to determine the distance between the smartphone and an object (such as your ear) during a call. The principle of operation is based on infrared radiation: the sensor emits an invisible beam and analyzes the reflected signal. If the obstacle is too close (usually at a distance of 2-5 cm), the system interprets this as “the phone is brought to the ear” and turns off the screen.

The Redmi Note 8 Pro uses a sensor model STK3311 (or its analogue), which is integrated into the common sensor board along with the light sensor, and it is important to understand that this module is not only responsible for locking the screen during calls, but also participates in other scenarios:

• 📞 Automatically turn on/off screen when holding phone to ear during conversation.
• 🔄 Preventing accidental taps on the touchscreen (for example, when the phone is in your pocket).
• 🎧 Optimizing headset: If the sensor detects that the phone is far from the ear, the sound can automatically switch to the speaker.
• 🔋 Saving battery power by turning off screen lights at unnecessary moments.

But the proximity sensor is not perfect, and it depends on a few factors:

• 🛠️ Sensor cleanliness: Dust, dirt, or protective glass can block the infrared signal.
• 📱 Version of the firmware: in some assemblies MIUI (especially custom sensors, the sensor can be disabled at the software level.
• 🔧 Physical damage: Falls or moisture often disable the sensor.

Standard way to enable proximity sensor through MIUI settings

In most cases, the proximity sensor on the Redmi Note 8 Pro is activated by default, but sometimes it can be disrupted after updating the firmware or resetting the settings. To make sure the sensor is on, follow the following steps:

1. Open the Settings app (the gear icon on the home screen).
2. Go to About Phone → All settings (or additionally, depending on the version of MIUI).
3. Find Proximation Sensor or Sensor Calibration. In some firmware, this section may be called Special Opportunities → Physical buttons.
4. Make sure that the switch next to the option The proximity sensor is in the position of On.
5. If there is a Calibration or Test button, press it and follow the instructions on the screen (usually you need to close the sensor with your hand and wait for confirmation).

If your MIUI version doesn't have an explicit point to turn on the sensor, it doesn't mean it's disabled. In recent firmware builds (e.g. MIUI 12.5 and later), the proximity sensor settings can be hidden in System settings → Additional. Alternative path:

Settings → Applications → Application Management → Phone → Permissions → Sensors

Important! On some custom firmware (like LineageOS or Pixel Experience), the proximity sensor may require a separate setup via the engineering menu, which we'll discuss in the next section.

Go to phone settings | Find the "approach sensor" section | Make sure it's on | Calibrate (if available) | Test during the call-->

Alternative activation methods: engineering menu and ADB-team

If standard settings don’t work, or you’re using unofficial firmware, the proximity sensor can be enabled via an engineering menu or ADB (Android Debug Bridge) these methods require caution, as improper actions can disrupt the phone.

Method 1: Engineering menu (code ##6484##)

This method works on most Xiaomi smartphones, including the Redmi Note 8 Pro:

1. Open the Phone app.
2. Enter the combination: ##6484## (some firmware may require ##4636###).
3. You will be taken to the engineering menu. Go to the Hardware Testing → Sensor section.
4. Find the Proximity Sensor and click on it.
5. In the window that opens, you'll see the current readings of the sensor, and you'll close it with your hand, and it should change from 5.0 cm (or similar) to 0.0 cm.
6. If the sensor is not responding, try pressing Calibrate.

Method 2: ADB-Teams (for experienced users)

If the engineering menu is not available, you can try to turn on the sensor through ADB.

1. Install ADB and Fastboot Tools on your computer.
2. Turn on USB debugging on your phone: Settings → About Phone → MIUI version (click 7 times to activate Developer Mode), then go back to Settings → Additional → For Developers and turn on USB debugging.
3. Connect your phone to your PC and type in the command line: adb shell settings put system proximity_delay 0 This command resets the sensor's delay.
4. To check the current state of the sensor, use: adb shell dumpsys sensorservice In the output, find the line with Proximity Sensor.

Warning: Changing settings through an engineering menu or ADB can cause the phone to run unstable.Do not change settings unless you are sure of their purpose!

How to check the operability of the proximity sensor without a call

You don't have to wait for an incoming call to make sure the proximity sensor is working correctly. There are several ways to manually test it:

Method 1: Application for testing sensors

The easiest way is to install one of the specialized apps from Google Play:

• 📱 Sensor Test (from Innovative Apps) – shows all available sensors and their current values.
• 🔍 Phone Doctor Plus – performs a full phone diagnostics, including a proximity sensor check.
• 🛠️ CPU-Z — In the Sensors section, data from the proximity sensor is displayed in real time.

Once installed, open the app, find the Proximity Sensor section, and close the sensor with your hand. The value should change from Far (far) to Near (close).

Method 2: Manual check by dialing

If you do not want to install third-party programs, use the standard Phone application:

1. Open the Phone app and dial any number (e.g. 123).
2. Press the call button, but don’t wait for the connection – immediately bring your hand to the top of the screen (where the sensor is located).
3. The screen should go out in 1-2 seconds. Remove your hand, the display will light up again.

Method 3: Verification through Android Hidden Settings

Android has a hidden section for testing sensors.

1. Open the Phone app.
2. Enter the code: ##4636###.
3. Select Usage Statistics (Usage Statistics) → Sensor test.
4. Find the Proximity Sensor and check for your hand's reaction.

If the sensor does not respond to either method, the problem may be hardware (sensor damage) or software (firmware failure), in which case it is recommended to reset the settings to the factory or contact the service center.

Typical proximity sensor problems and their solutions

Even if the sensor is on, it can work incorrectly, and let's look at the most common faults and how to fix them:

One of the most insidious problems is false positives, where the screen goes out for no reason, and it's often because of:

• 🧴 Fat marks on the sensor (for example, from hand cream).
• 📦 Poor-quality protective glass that blocks infrared signal.
• 🔄 Conflict with third-party applications (for example, battery saving software).

If the problem occurs after installing a new glass, try temporarily removing it and testing the sensor, sometimes just gluing the glass, leaving the sensor area free.

💡

To quickly check if the safety glass is to blame, blow to the top of the screen (where the sensor is located). If the screen goes out, then the glass is blocking the signal and it needs to be replaced.

Calibration of the proximity sensor: when and how to conduct it

Calibration of the proximity sensor on the Redmi Note 8 Pro is required in several cases:

• 🔄 After the firmware update (especially if the version is updated) MIUI It has changed significantly, for example, from 11 to 12).
• 🛠️ After replacing the screen or protective glass.
• ⚡ If the sensor starts to work unstable (for example, the screen goes out with a delay or does not turn back on).

The calibration process is simple, but requires care:

1. Open the engineering menu (code ##6484##).
2. Go to Hardware Testing → Sensor → Proximity Sensor.
3. Press Calibrate.
4. Follow the instructions on the screen: you usually need to alternately close and open the sensor with your hand 3-5 times.
5. Once completed, restart the phone.

If your firmware doesn’t have a calibration option, you can use Google Play’s Sensor Calibration app, which supports most Xiaomi smartphones and allows you to manually adjust the sensor sensitivity.

Attention! ⚠️ Do not calibrate if the sensor is physically damaged (for example, after a phone crash) this can aggravate the problem.

What to do if the proximity sensor does not work after the MIUI update

One of the most common causes of proximity sensor failure is a firmware update, especially for users who install MIUI bats or custom builds, and if the sensor stops working after the update, try the following steps:

1. Reboot your phone. Sometimes it helps to reset the temporary driver errors.
2. Clear the system cache: Settings → About phone → Memory → Cleanup → Cash
3. Reset the settings of the phone application: Settings → Annexes → Application management → Phone. → Warehouse → Clear the data Attention! ⚠️ It'll delete the call history.
4. Reverse to the previous version of MIUI (if the problem occurred after the update). To do this: Download the old firmware from the official Xiaomi website. Go to Settings → About Phone → System Update. Click on the three dots in the upper right corner and select Select the firmware file.

Install a patch for the sensor

4PDA

XDA Developers

If neither method worked, the problem may be that the firmware core is incompatible with the sensor drivers, leaving two options:

• 🔄 Wait for the official fix from Xiaomi (watch out for updates in Settings section) → The phone. → Updating the system).
• 🛠️ Refuse the phone to another assembly MIUI (European to European or vice versa).

💡

If the sensor stopped working immediately after the update, in 90% of cases the software is to blame, not the hardware.

FAQ: Frequent questions about the proximity sensor on the Redmi Note 8 Pro