How to set up the proximity sensor on Xiaomi Redmi Note 8: the full guide

The proximity sensor in the Xiaomi Redmi Note 8 is a small but critical component that is responsible for automatically turning off the screen during phone calls. When you hold your smartphone to your ear, the sensor registers the obstacle and extinguishes the backlight, preventing accidental pressing and saving battery power. However, users often face problems: the screen does not go out when you call, the sensor is triggered with a delay or works unstable after a firmware update.

In this article, we’ll look at all aspects of the Redmi Note 8’s proximity sensor setup, from basic health checks to manual calibration and hardware tests, how to diagnose malfunctions, fix software failures, and when to contact a service center, and focus on hidden MIUI settings that the manufacturer doesn’t advertise, but can solve the problem without resetting to factory settings.

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

The proximity sensor in the Xiaomi Redmi Note 8 is an infrared sensor located at the top of the screen next to the front camera.

• 🔦 Infrared emitter emits an invisible light signal;
• 📡 Photodetector – captures the reflected signal and determines the distance to the object.

When you hold your phone to your ear, the face-reflected signal is picked up by the sensor and the system turns off the screen. The Redmi Note 8 uses a model STK3311 sensor (or similar), which is integrated into the general module with the light sensor. It is important to understand that failures in its operation can be associated with both software errors MIUI, and physical damage (for example, after a fall or moisture).

The sensor is activated not only during calls, but also when using some applications, such as Google Assistant or Mi Voice, where voice control requires locking the screen, and if the sensor is faulty, this can lead to false positives or, conversely, to a lack of response.

Signs of malfunction of the proximity sensor

Before you start setting up, it’s important to make sure the problem is really related to the proximity sensor, and here are the typical symptoms of it not working properly on the Redmi Note 8:

• 📵 The screen does not go out when you hold the phone to your ear during a call (remains active, leading to occasional taps);
• 🔄 The screen goes out arbitrarily, even when the phone is lying on the table or in your pocket;
• ⏳ Delayed operation - the screen goes out through 2-3 seconds after touching the ear;
• 🔦 In the dark, a faint glow is visible in the sensor area (indicates damage to the emitter);
• 📱 Applications that use the sensor (e.g. Pocket Mode) are unstable.

If you see at least one of these signs, the problem may be:

• 📲 Software failure (for example, after updating) MIUI);
• 🔧 Incorrect settings (disabled function or downed calibration);
• 🛠️ Hardware failure (damage to sensor or plume).

⚠️ Attention: If the sensor stops working after the phone falls or moisture gets in, there is a high probability of physical damage, in which case the adjustment by software methods will not help - you will need to replace the module.

How to check the operation of the proximity sensor on the Redmi Note 8

Before you set up the sensor, make sure it works at all. Use built-in MIUI tools or third-party apps to do this.

Method 1: Testing through the Engineering Menu

The most reliable way is to use a hidden engineering menu.

1. Open the phone application;
2. Enter the combination: ##6484##;
3. Select the Proximity Sensor option.
4. Raise your hand to the top of the screen – the value should change from 5.00 cm to 0.00 cm.

If the values don't change or if the error is displayed, the sensor is faulty. If there is a reaction, but with a delay, calibration is required.

Method 2: Checking with Sensor Test

Download the Sensor Test app from Google Play (like Phone Doctor Plus) and run the proximity sensor test:

• 📱 Open the Proximity section;
• 🖐️ Close the sensor with your hand – the screen should go out or display the Covered message;
• 🙌 Remove your hand, the screen must be activated again.

⚠️ Attention: Some shells (e.g, MIUI 12+) They can block access to sensors for third-party applications. If the test doesn't work, use the engineering menu.

Make sure there is no protective film or glass on the screen |Close all background apps |Plug your phone to charge (recommended) |Put backup of settings-->

Configure the proximity sensor through the MIUI menu

If the sensor is working but is not stable, try setting it up using standard MIUI settings. Depending on the firmware version, the path to settings may vary.

Step 1: Enable the screen lock function during the call

Sometimes the problem is that you have the option turned off, and you can check it like this.

1. Go to Settings → Applications → Phone;
2. Select Incoming Calls;
3. Activate the option to lock the screen during a conversation (or proximity sensor).

Step 2: Calibration of the sensor

MIUI allows you to manually calibrate the sensor if it's running late.

1. Enter the code in the phone application: ##6484##;
2. Select Proximity Sensor;
3. Press Calibrate (if the option is available)
4. Follow the instructions on the screen (usually you need to bring and remove your hand several times).

If there is no calibration option, try resetting the sensor settings through the engineering menu (Clear Calibration).

Step 3: Reset the settings of the Phone application

Sometimes, failures are caused by corruption of the application's data, to reset its settings:

1. Go to Settings → Applications → Application Management;
2. Find the phone and select it;
3. Press Warehouse. → Clear the data;
4. Reboot the phone.

⚠️ Warning: Clearing the data from the phone app will delete the call history. Pre-export it if it's important.

Manual sensor setup via ADB (for advanced users)

If standard methods don’t work, you can try changing the sensor parameters via the Android Debug Bridge (ADB), a method that is suitable for users familiar with the command line.

Step 1: Preparation

The work will require:

• 💻 A computer with installed Xiaomi drivers and ADB;
• 📱 Included debugging by USB on the phone (Settings) → The phone. → Version. MIUI → Press 7 times, then additionally → For developers → Debugging by USB);
• 🔌 USB-cable (preferably original).

Step 2: Check the current sensor values

Connect your phone to your PC and do the following at the terminal:

adb shell


su




cat /sys/class/sensors/proximity/proximity_raw

Put your hand in the sensor, the values should change from 5 to 0. If there is no change, the sensor is malfunctioning at the hardware level.

Step 3: Change of thresholds

Sometimes it helps to adjust the trigger threshold.

1. Open the sensor configuration file: Adb pull /vendor/etc/sensors/proximity_calibration.xml
2. Edit the parameters threshold_near and threshold_far (For example, change the 5.0 on 3.0);
3. Save the file and download it back: adb push proximity_calibration.xml /vendor/etc/sensors/ adb shell chmod 644 /vendor/etc/sensors/proximity_calibration.xml
4. Reboot the phone.

Warning! Incorrect editing of system files can cause the phone to function in an unstable way. Before making changes, back up the original file.

💡

If after editing the sensor stopped working completely, return the original file or reset settings through Settings → Additional → Restore and reset.

Hardware problems: when you need to replace the sensor

If all software methods have been tried, but the proximity sensor on the Redmi Note 8 still doesn't work, the problem is likely hardware.

The cost of replacing the proximity sensor with the Redmi Note 8 in service centers is from 800 to 1500 rubles (depending on the region).

• 🛠️ You will need a special tool (suction cup, mediator, screwdriver). T3);
• 🔋 Risk of damage to battery plume or display;
• 📦 The sensor is usually assembled with a light module (set price) ~500-700 ruble.).

⚠️ Note: When replacing the sensor, turn off the battery 10-15 It's a way to prevent short circuits from accidentally touching the contacts.

💡

If the sensor stopped working after a fall or impact, don't try to calibrate it programmatically, it's useless. In 90% of cases, you'll need a physical replacement of the module.

Frequent errors in setting up the proximity sensor

Many users make mistakes that only make the problem worse, and here are the most common ones:

• 🔄 Ignoring updates MIUI — In new versions of firmware often fix bugs with sensors;
• 📱 Use of non-original protective glass – thick glass can block infrared signal;
• 🔧 Resetting settings without backup – this leads to data loss;
• 🛠️ Self-disassembly without experience - a high risk of damaging plumes;
• 📵 Disable debugging by USB after ADB-Settings – This can reset changes.

Another common mistake is trying to calibrate the sensor through applications like Proximity Sensor Reset, which often don’t have access to MIUI system files and simply simulate calibration without solving the problem.

If you are not sure about your actions, it is better to contact the Xiaomi service center. Official workshops use special diagnostic equipment (for example, Mi Diagnose Tool), which more accurately determines the cause of the malfunction.

FAQ: Answers to Frequent Questions