Xiaomi’s modern smartphones store vast amounts of sensitive information, from banking apps to personal correspondence, so protecting access to the device becomes a priority. Using biometric data like a fingerprint provides not only a high level of security, but also a significant convenience in everyday use of the gadget. You no longer need to enter a complex digital code or pattern lock every time, just one touch is enough.
The process of activating the scanner on the shells of MIUI and the new HyperOS is as simplified as possible by developers, but many users are unaware of hidden settings that can improve the responsiveness of the sensor. In this article, we will discuss in detail how to correctly add a fingerprint, what are the nuances of the sensors under the screen, and how to act if the system stops recognizing your finger.
It should be noted that the quality of the scan depends on the condition of the surface of the finger and the screen itself. Dirt, moisture or low-quality protective film can significantly reduce the speed of unlocking, so before you start setting up, it is recommended to wipe the display and hands. Next, we will move to the step-by-step instructions that will help you adjust the biometrics in a few minutes.
Device preparation and system requirements
Before you start directly registering fingerprints, you need to make sure that your device is ready to work with biometric data, PIN-code or pattern lock, because they are the backup method of access in the event of a sensor failure, without this basic security element, the system will not allow the scanner to be activated.
It is also important to check the validity of the operating system version, as older MIUI builds may have had bugs affecting the security module. Go to the settings menu and look for the About Phone section to make sure you have the latest available firmware for your model installed.
Note the cleanliness of the scanning area: if you have a model with a sensor under the screen, any contamination will interfere with the reading of the pattern of papillary lines. For models with a side or rear scanner, the dry surface requirement is also important, since moisture can distort the signal.
☑️ Checking before setting up
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If you use thick protective glass, when registering a fingerprint, slightly press the screen so that the sensor better reads the relief of the finger through the glass.
Step-by-step instructions for adding a fingerprint
The process of adding a new fingerprint begins by entering the main settings menu of your Xiaomi smartphone.Look for the Passwords and Security section or simply Fingerprints, which is usually located at the top of the settings list.
After successful authorization, press the Add Fingerprint button and apply the specified finger to the scan area. The screen will vibrate or emit an audible signal every time you successfully read the area, gradually filling in the pie chart on the display.
It's critical that you don't just stick your finger statically, but change the angle of your finger at each step so that the system remembers the edges and the center of the pad. If you keep your finger flat, unlocking in real use may not work when you take your phone in a natural grip.
⚠️ Note: Do not register the same finger twice under different names, this can confuse the algorithm of security priorities and slow down the sensor.
To improve reliability, it is recommended to add both thumbprints, as they are the ones most often unlock the device in different positions of the hands.The system allows you to save up to 5 different fingerprints, which makes it possible to configure access for trusted persons or use different fingers to quickly launch applications.
Setting up functions and quick actions
Modern Xiaomi smartphones allow you to use the fingerprint scanner not only to unlock the screen, but also to perform various quick actions. In the fingerprint management menu, you will find the item “Short press” or “Long press”, which can be assigned to start the camera, flashlight or payment through Google Pay and Mi Pay.
One of the most useful features is the ability to unlock running apps, so you can set up fingerprint access for gallery, messengers or bank customers, creating an additional layer of data protection, which is especially true if the phone is used by children or if the device can fall into the hands of unauthorized people.
There is also a “Unlock in your pocket” feature that allows you to remove the phone and unlock it in one motion without pressing the power button separately, but it is worth considering that turning on this option can slightly increase battery consumption due to the constant activity of the sensor in standby mode.
Hidden capabilities of the scanner
Features of the operation of optical and ultrasonic sensors
Xiaomi devices use two main types of scanners built into the screen: optical and ultrasonic. Optical sensors, which are more common in the middle segment, take a picture of a finger and compare it to a saved standard, requiring good lighting or pixel backlight to work.
Ultrasonic sensors, characteristic of flagship models, use sound waves to create 3D-mapping your finger surface, making them more reliable and faster, especially when you have wet hands. Understanding the type of sensor you have helps you adjust your sensitivity and understand the device's limitations.
Optical scanners are critical to the brightness of the screen when they touch, so the system can automatically brighten when they try to unlock, while ultrazoozoid scanners are less dependent on external conditions, but may require a tighter finger to the surface of the glass.
| Characteristics | Optical sensor | Ultrasonic sensor |
|---|---|---|
| Principle of work | 2D light scanning | 3D Sound Waves |
| Working with moisture | Hard to do. | Stable. |
| Response speed | Medium | Tall. |
| Energy consumption | Low. | Average. |
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Knowing the type of sensor you have helps you understand why under certain conditions (wet hands, bright sunshine) the unlock speed can change.
Management of stored data and deletion
During operation, you may need to delete previously stored fingerprints, for example, if you have tied a finger or just want to clean the list of unused data. To do this, select a specific entry in the fingerprint menu and click the “Delete” button, confirming the action with a password.
Full reset of all biometric data occurs automatically when the phone resets to factory status or when the main unlock password is changed, an important security measure that ensures that old data is not used to access the updated system.
It is recommended to periodically re-register the fingerprints, especially if you notice a decrease in the sensor response rate. Over time, the microrelief of the finger can change due to calluses or seasonal features of the skin, so updating the standard will help maintain a high speed of operation.
⚠️ Note: Deleting all fingerprints does not disable the biometrics function completely, but makes it impossible to unlock before adding new data.
Solving common problems and failures
Sometimes users are faced with a situation where the phone no longer recognizes the previously registered finger, most often the problem lies in the contamination of the sensor or screen, so the first step should always be a thorough wipe of the scanning area with a soft cloth.
If physical cleaning didn't work, try restarting the device, because the system process responsible for biometrics might have stalled, and in rare cases, you need to re-register the fingerprint from scratch, paying special attention to the edges of the finger.
In situations where the sensor is unstable after a firmware update, cleaning the Settings app cache or resetting the biometrics settings can help. Don’t ignore the problem, as it can indicate a software conflict that is easier to resolve early.