Where to turn on the proximity sensor on Xiaomi Redmi Note 8: a complete guide with pictures

The proximity sensor in the Xiaomi Redmi Note 8 is a small but critical element that is responsible for automatically turning off the screen during a phone conversation. When you hold your smartphone to your ear, the sensor detects the obstacle and extinguishes the display, preventing accidental pressing and saving battery power. However, many users face the problem: the screen does not turn off when you call or, conversely, goes out for no reason, most often due to improper settings or accidental disconnection of the sensor.

In this article, we will discuss in detail where the approach sensor control option in the Redmi Note 8’s MIUI firmware is located, how to turn it on (or off), and what to do if it does not work correctly. We will pay special attention to hidden settings that are not always obvious to beginners, and common errors that can cause the sensor to “glut”, if you notice that during a call the screen does not go out or, on the contrary, turns off too early, this instruction will help to return everything to normal.

What is a proximity sensor and why you need it

The proximity sensor is an optical sensor located at the top of the Redmi Note 8 screen (near the speaker and the front camera), which works on the principle of infrared radiation: it emits an invisible beam and tracks its reflection from objects. When you hold the phone to your ear, the beam reflects back, and the sensor “knows” that the screen needs to be turned off.

The main functions of the sensor:

• 📞 Turning off the screen during a call – prevents accidental tapping of the cheek or ear.
• 🔋 Battery savings – the screen consumes a lot of power and turning it off prolongs the running time.
• 🛡️ Protection against false positives – for example, when the phone is in your pocket or bag.

On the Redmi Note 8, the proximity sensor is integrated into the STK3338 module (or similar), which is also responsible for the illumination of the screen. If it fails or is switched off programmatically, this leads to discomfort when calling: the screen can remain on, respond to touches or spontaneously go out.

Where is the proximity sensor setting in MIUI

Unlike many other smartphones where the proximity sensor is controlled through call settings, MIUI for Redmi Note 8 this option is hidden deeper. Moreover, in some versions of the firmware option may not be on the menu at all – it depends on the regional build and the version of MIUI (for example, in the global version the path is different from the Chinese).

The standard way to set up:

1. Open the Settings app (the gear icon on the desktop).
2. Go to the System Applications section.
3. Choose Phone (or Calls, depending on version).
4. Slap on the incoming calls.
5. Find the option of Approach Sensor (or Auto-Switch Off Screen).

If you don't have this in your firmware, don't panic, there are alternatives. For example, in some MIUI 12/13 builds, the option is moved to Settings → Display → Automatic Screen Disconnect. It's also worth checking the Additional Settings → Special Features → Physical buttons, where sensor settings sometimes hide.

Find the "Phone" section in system applications |

Check for the option "approximation sensor" |

Make sure the slider is on (active) |

Reboot your phone after the changes-->

Step-by-step: how to turn on the proximity sensor

If you find an option in the settings but it is disabled, follow this instruction:

1. Open Settings → System applications → Phone → Incoming calls.
2. Find the Proximation Sensor (or Auto-Switch off screen when calling).
3. Activate the slider (it should turn blue or green).
4. Save the changes and restart the phone (this will help you apply the settings correctly).

If there is no option, try to enable it through the developer mode:

1. Go to Settings. → The phone.
2. Tap 7 times on the MIUI version until the notification “You became a developer” appears.
3. Return to Settings → Additional settings → For developers.
4. Find the USB Debugging option and turn it on (this will unlock hidden settings).
5. Scroll down and check for the presence of the Approach Sensor or Sensor Off item.

Important: On some Redmi Note 8 firmware (especially custom ones), the proximity sensor can be turned off at the kernel level, in which case only flashing or resetting to factory settings will help.

How to check the operation of the proximity sensor

Before you sin on the settings, make sure that the sensor is working. There are several ways to do this:

Method 1: through the Engineering Menu

1. Open the Phone app.
2. Enter the combination ##6484## (or #4636## for some versions).
3. Select Proximity Sensor (proximity sensor).
4. Raise your hand to the top of the screen – the value should change from 5.00 (no obstacle) to 0.00 (there is an obstacle).

Method 2: Using a third-party application

Install Sensor Test or CPU-Z from Google Play. In the Sensors section, find Proximity and check for your hand’s response.

If the sensor is not responding:

• ⚠️ Check if there is a protective film or glass on the screen that blocks the infrared signal.
• ⚠️ Make sure there is no dirt or damage at the top of the phone.
• ⚠️ Try calibrating the sensor (more on that below).

Calibration of the proximity sensor on the Redmi Note 8

If the sensor is unstable (for example, the screen is turned off with a delay or does not turn back on), it can be calibrated.

1. Install the Proximity Sensor Reset app from Google Play.
2. Run it and follow the instructions on the screen (usually you need to hold and remove your hand from the sensor several times).
3. Reboot the phone.

Calibration can also be done through the engineering menu:

1. Open the menu with ##6484##.
2. Select Proximity Sensor.
3. Press Calibrate and follow the hints.

If calibration didn’t work, the sensor may be physically damaged, which would require a replacement at a service center, and the cost of repairs for the Redmi Note 8 is usually between 1,000 and 1,500 rubles (depending on the region).

💡

Before calibration, remove the cover and protective glass – they can distort the sensor signal.

Common Problems and Their Solutions

Even after the sensor is turned on, Redmi Note 8 users may experience problems.

If the problem persists after all the manipulations, try resetting your phone to factory settings:

1. Go to Settings → About the phone → Reset settings.
2. Select Reset all settings (does not delete files, only settings).
3. Confirm the action and wait for the reboot.

💡

Resetting is a last resort. Before you do that, be sure to check the sensor in safe mode (press the power button → Safe Mode) to exclude the influence of third-party applications.

What to do if the proximity sensor is broken

If the sensor does not respond to calibration and checks show it is malfunctioning, there are two options:

1. Replacement of the sensor in the service center. On the Redmi Note 8, the proximity sensor is soldered into the plume along with the front camera and speaker, so replacing it requires disassembling the phone. The cost of work is from 800 to 1,500 rubles (plus the price of spare parts, if necessary).
2. If you don't use phone calls or are willing to put up with inconvenience, you can deactivate the sensor: Through call settings (turn off the proximity sensor option). Through the engineering menu (find Proximity Sensor and deactivate it).

Before you carry your phone for repair, check:

• 🔍 Are there any cracks or chips in the sensor area on the screen.
• 💧 Has not got moisture in the phone (even a small amount can knock the sensor out of order).
• 🔌 Whether there were falls or impacts – the sensor is sensitive to mechanical damage.

⚠️ Note: If you decide to replace the sensor yourself, consider that the Redmi Note 8 has a fragile plume.Incorrect disassembly can damage the camera or microphone.

FAQ: Answers to Frequent Questions