Xiaomi Poco F3 has a useful feature called the pocket mode, which automatically locks the screen when the device hits your pocket or bag, which prevents accidental taps, saves battery power and protects against unwanted actions. However, sometimes the sensor works too aggressively: the screen does not turn on when you talk, does not respond to touch or, conversely, does not lock at the right moment.
If you encounter these problems, don't rush to bring your phone to the service. 90% of the time, it's enough to turn off or reconfigure the mode in your pocket through standard MIUI settings. In this article, we'll look at all the ways to control the function, from basic disconnection to fine-tuning the proximity sensor, and how to check the sensor's performance and what to do if the screen stops responding after a firmware update.
What is the mode in the pocket and how it works on the Poco F3
Pocket Mode is a hardware-software function that uses a proximity sensor and an accelerometer to detect when a smartphone is in a closed space (pocket, bag, case).
- 🔄 The screen is locked even if you press the power button.
- 📵 Touch taps are turned off (to avoid accidental calls or app launches).
- 🔋 Reduces energy consumption by turning off the lights.
On the Poco F3, the function is handled by a sensor called STK3338 (or similar) located next to the top speaker, which responds to the approach of objects up to 5 cm. If the sensor is dusty, damaged or miscalibrated, there may be failures: the screen does not unlock when you call, spontaneously turns off during games or, conversely, does not lock in your pocket.
How to completely disable the mode in your pocket on Poco F3
If the feature interferes with normal phone use, it can be completely deactivated.
- Open the settings (cog icon on the desktop).
- Go to the Screen section.
- Select Mode in your pocket (or Lock in your pocket depending on the MIUI version).
- Move the slider to the off position.
Once turned off, the smartphone will stop automatically locking the screen in your pocket, but note that this can lead to accidental pressing (for example, while walking) and accelerated battery discharge if the screen lights up in the bag.
Screen settings open|Found item "Mode in the pocket"|Slider moved to "Off" position."|Phone reloaded (optional)-->
⚠️ Attention: On some firmware MIUI 13/14 This can be called Autolock or Approximation Sensor. If you don't find it in the Screen section, check for Additional settings. → Special facilities.
Fine settings in the pocket (without completely switching off)
If you don't want to turn off the function completely, but you need to adjust its operation, use additional parameters. F3 The following options are available:
| Parameter | Description | Recommended value |
|---|---|---|
| Sensitivity of the sensor | Determines how close an object must be to trigger a lock. | Medium (balance between reliability and false positives) |
| Lockdown delay | The time it takes for the screen to lock after it hits your pocket. | 2-3 seconds (enough for most scenarios) |
| Ignore during the call | Disables the lock if you are talking on the phone. | On (solves the black screen problem when calling) |
| Work in a horizontal position | It locks the screen even if the phone is on the table with the screen down. | Off (may interfere with watching video) |
To change these parameters:
- Go to Settings → Screen → Mode in your pocket.
- Click on Additional settings (or Sensor Settings).
- Adjust the sliders or turn on/off the options according to the table above.
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If the sensor is unstable after changing the settings, calibrate: go to Settings → About Phone → All specs, then 5 times click on the Proximity Sensor. A testing menu will appear where you can check the sensor response.
Problems with the mode in the pocket after the MIUI update
Many Poco F3 users are faced with the fact that after updating the firmware (especially on MIUI 13/14), the mode in the pocket begins to work incorrectly: the screen does not unlock, the sensor does not respond to an approach or, conversely, it works for no reason.
- 🐞 Firmware bug - in some assemblies MIUI broken logic of the sensor.
- 🔄 Resetting settings - after the update, the mode parameters return to the factory.
- 📱 shell conflict – if you use third-party launchers (like Nova Launcher), they may interfere with the sensor.
Decisions:
- Reset the sensor settings: go to Settings → Applications → Application Management → All applications, find Sensors (or Sensor Service), clear the cache and data.
- Reverse to the old version of MIUI: If the problem has appeared after the update, try going back to the previous firmware via Fastboot.
- Install a patch: XDA Developers or 4PDA forums often post patches for sensor bugs.
⚠️ Warning: If the screen has stopped responding to touches after the update, it may not be due to the mode in the pocket, but to damage to the display plume.
How to check the operability of the sensor of approach
Before you set or turn off the mode in your pocket, make sure that the proximity sensor is working correctly.
- Type the code ##6484## (or #4636## → Testing → Sensors) on your phone keyboard.
- In the menu that opens, find Proximity Sensor.
- Close the top of the phone (where the speaker is located) with your hand, and the value should change from 5.0 cm to 0.0 cm.
- Remove your hand – the value should return to 5.0 cm.
If the sensor is not responding:
- 🧹 Clean the area around the speaker of dust and dirt (use a soft brush or compressed air).
- 🔧 Check if the glass screen is damaged (cracks can block the signal).
- 📱 Reset your phone settings to factory (pre-reverse your phone).
What if the sensor shows the wrong values?
Alternative ways to lock the screen in your pocket
If the standard mode in your pocket is unstable, but you still want to protect yourself from inadvertent taps, consider alternative methods:
- 🔒 Double-click to lock: enable the option in Settings → Screen. → Double-touch locking, and now the screen will only lock after two quick presses.
- 📱 Lock gesture: in MIUI You can configure the swipe gesture down the screen for instant locking (path: Settings) → Gestures → Lock screen gestures).
- 🛡️ Third-party applications: utilities like Gravity Screen or Proximity Service allow you to flexibly configure automatic locking on the proximity sensor and accelerometer.
Alternative methods have the advantage of being more reliable, as they don’t depend on the Poco F3 sensor, but third-party applications can drain the battery faster because of the constant monitoring of sensors.
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If you use a magnetic lock case, the mode in your pocket can be turned off completely - the magnet will automatically lock / unlock the screen when you open the case.
Frequent errors when setting up the mode in your pocket
Many users make common mistakes that cause the sensor to malfunction.
- 🚫 So you can tape it with film or glass, and even a thin protective film can block the infrared signal, which will stop the sensor from responding.
- 🚫 Disable all permissions for the Sensor app, which will result in complete inoperability of the pocket mode and other functions (for example, automatic brightness adjustment).
- 🚫 Use non-original firmware without patches. ROM-(e.g. LineageOS) often do not support the correct operation of the proximity sensor on Poco F3.
Also, avoid extreme temperature changes – if you leave your phone in the cold and then bring it into a warm room, the sensor can temporarily fail due to condensation, in which case it is enough to wait 10-15 minutes while the smartphone adapts to the temperature.