Approximation Sensor on Xiaomi Redmi 10S: how to turn on, configure and check

Xiaomi Redmi 10S is a popular smartphone with a balance of price and functionality, but some users face a problem: during a call, the screen does not go out when approaching the ear, the fault is often a disabled or improperly working proximity sensor, in this article we will discuss how to activate it, check it and what to do if it does not respond.

The proximity sensor is responsible for automatically turning off the screen during a call to prevent accidental taps. On the Redmi 10S (model m2109), it is located next to the front camera and works on the basis of infrared radiation. If you notice that the screen remains active when you call or, conversely, goes out for no reason, the problem can be in settings, sensor contamination or software failure.

Why you need a proximity sensor and how it works on the Redmi 10S

The main purpose of the sensor is to save battery power and prevent false touches during a call. When you hold the phone to your ear, the sensor picks up the obstacle and sends a signal to the system to turn off the backlight. The Redmi 10S uses STK3311, a combined chip that combines proximity and illumination sensors.

Signs of malfunction:

• 📵 The screen does not go out when you call (remains on despite the approach to the ear).
• 🔦 The lights are switched off arbitrarily, even when the phone is lying on the table.
• 📱 At the top of the screen appears a notification “approach sensor is blocked».
• 🔄 The sensor is triggered with a delay (for example, the screen goes out 2-3 seconds after the application).

If the sensor is completely out of order, it will cost 800-1,500 rubles (depending on the service center), but in 80% of cases the problem is solved software - just turn on or reset the settings.

How to turn on the proximity sensor through the settings of Redmi 10S

By default, the sensor is activated, but after updating MIUI or resetting the settings, it can turn off.

1. Open Settings (the gear icon on the main screen).
2. Go to the About Phone section. → All characteristics.
3. Find the Sensors string and tap it.
4. In the list, check the item Approximation Sensor - next to it should be the value Works.

If the sensor is turned off or the system cannot see it:

• 🔧 Restart your phone (hold the power button for 10 seconds).
• 📲 Update. MIUI Up to the latest version in Settings → Updating the system.
• 🧹 Clear the sensor cache: Settings → Annexes → Application management → Three dots (menu) → Show system-based → Sensor Service → Clear the cache.

Checking the proximity sensor using the engineering menu

If the standard settings do not show the status of the sensor, use an engineering menu, which is suitable for advanced users, since careless actions can disrupt the operation of the phone.

Instructions:

1. Open the phone app and enter the combination: ##6484###
2. Select Proximity Sensor (approximation sensor).
3. Put your hand to the top of the screen and change from 5 (no obstacle) to 0 (obstacle detected).
4. If the numbers don’t change, the sensor is faulty or contaminated.

Important: Some firmware may not have an engineering menu or require root permissions, in which case use third-party apps, such as the Sensor Test from Google Play.

Cleaning the proximity sensor: step-by-step instructions

A common cause of failure is contamination of the infrared sensor, dust, greasy prints or residues of protective film block the signal, cleaning takes 2-3 minutes and does not require disassembling the phone.

You'll need:

• 🧴 Alcohol wipes (or cotton swab) + isopropyl alcohol 70%).
• 🔦 Lantern (to illuminate the sensor area).
• 🧲 Lupa (optional, for accurate cleaning).

How to clean:

1. Turn off the phone.
2. Moisten the cotton swab with alcohol and gently wipe the area next to the front camera (see photo below). Don't press hard - the sensor is fragile!
3. Remove the remaining moisture with a dry wipe.
4. Turn on the phone and check the sensor through the engineering menu.

⚠️ Warning: Do not use abrasive materials (such as paper wipes) - they may scratch the sensor.

Sensitivity setting (for experienced users)

The Redmi 10S doesn’t have a standard slider for adjusting sensitivity, but it can be changed via ADB (Android Debug Bridge), a technique that requires connecting the phone to a PC and basic command line knowledge.

Instructions:

1. Turn on Developer Mode: Settings → About Phone → 7 times tap on the MIUI version.
2. Activate USB Debugging in Settings → Additional → For developers.
3. Connect your phone to your PC and execute the command: adb shell settings put system proximity_delay 1000 (where 1000 — delay time in milliseconds; by default — 500).
4. Reset the device.

⚠️ Warning: Incorrect values can cause the screen to go out too quickly or, conversely, not to respond. Recommended settings: 300 (fast-off) - 1500 (slow-off).

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If the sensor is unstable after changing the parameters, return the standard value with the command adb shell settings delete system. proximity_delay and reboot the phone.

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

Firmware updates sometimes reset the sensors or make errors in their operation.

1. Reverse to the previous version of MIUI (if backup is available).
2. Reset to factory settings: Settings → Additional → Restore and Reset → Reset Settings Attention: This Will Delete All Data From Your Phone!
3. Install Custom Recovery (TWRP) and manually run the sensor module (for advanced users).

If the reset didn’t help, check the error log:

• Install the Logcat Extreme app from Google Play.
• Start log recording and try activating the sensor.
• Look for lines with proximity or STK3311 in the log, which will indicate a specific error.

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Before resetting your settings, save important data (contacts, photos, messages) to the cloud or PC. Recovery after reset is not always smooth, especially if the sensor has been corrupted at the software level.

Alternative ways to control the screen during a call

If the sensor is not repairable, workaround solutions can be used:

• 📱 Manual screen shutdown: during the call, press the power button to extinguish the backlight.
• 🔄 Simulator applications: Proximity Sensor Fix or Gravity Screen simulate the operation of the sensor through the accelerometer.
• 📞 Headset usage: Connect Bluetooth headphones – the screen will turn off automatically when the phone is removed from the ear.
• 🛠️ Replacement of the sensor: in the service center (cost - from 800 rubles).

The disadvantage of alternative methods is increased battery consumption (for example, simulator applications keep the accelerometer active all the time).

FAQ: Frequent questions about the proximity sensor on the Redmi 10S