Xiaomi’s Redmi line of smartphones has long proven to be affordable and feature-rich. The Redmi 3S, which hit the market a few years ago, is still popular today for its robust metal body and optimal performance for basic tasks. One of the key safety features in this device is a biometric scanner located on the back of the case.
Turning on fingerprint protection not only protects personal data from unauthorized access, but also makes it much easier to unlock the screen. You no longer need to enter a digital password or draw a pattern lock every time. Biometric protection on Android works quickly and efficiently if you perform the original sensor settings correctly.
The process of activating this feature in the MIUI shell is intuitive, but beginners may have questions regarding the sequence of actions. In this article, we will discuss in detail each step necessary to add your fingerprint to the device memory. We will also look at possible problems and ways to solve them, so that your Xiaomi works as conveniently as possible.
Preparation of the device for setting up biometrics
Before you start directly registering fingerprints, you need to make sure that the smartphone is ready to work with the security module. MIUI requires certain preconditions to be met, without which the scanner will not be activated. First of all, check the battery power, as the setup process and subsequent use require stable power.
It's important to understand that in order for biometric protection to work, the device must have the basic method of locking the screen. PIN-The system uses this method as a backup option in case the sensor can not read your finger or after rebooting the device.
⚠️ Warning: Don’t choose too simple combinations like “1234” or “0000” as a backup password. 3S.
It is also recommended to wipe the back of the smartphone and the sensor itself with soft dry cloth. Fat spots or dust can interfere with the scanning process, which will lead to errors during the initial registration. Clean sensor surface is the key to successful reading of papillary patterns.
Navigation through the MIUI settings menu
The MIUI shell interface may be different from standard Android, so finding the right partition can sometimes be difficult for new users. All security settings are concentrated in a single control center. To get there, open the Settings app on the home screen or in the notification curtain.
In the list of options that opens, you need to find the section that is responsible for blocking and protecting data, and in different versions of the firmware it can be called Passwords and Security or simply Lock and Protect, and this is where all the tools for controlling access to the device are located.
Once you log in to the security section, you'll see a list of available authorization methods, and you'll see the options for setting your screen password, protecting your applications, and of course managing your fingerprints, and you'll see them navigate with standard taps across the screen.
If you haven't previously set an unlock password, the system will automatically redirect you to the scanner's creation screen when you try to activate the scanner. This is a mandatory Xiaomi security requirement that you can't bypass. Remember or write down the code you created, as it will be needed to confirm the actions in the system.
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Use the “Show Password” function when creating PIN-code to ensure that the characters are entered correctly and to avoid errors in memorization.
Fingerprint registration process
When you find "Add fingerprint" or "Manage fingerprints", click on it to start the scanning procedure. The screen will show a graphic image of the palm that will visualize the reading process. Place the finger you plan to use to unlock on the circular sensor on the back of the smartphone.
Hold your finger tightly, but don't push it too hard. Wait for a light vibration of the device that signals a successful reading of the first section, and then the system will ask you to change the position of your finger a little bit to count the edges and center of the pad.
☑️ Print scanning rules
The registration process consists of several steps, each of which requires scanning different parts of the finger, and the algorithm asks for the finger to move up, down, left and right, and this allows you to create a full-fledged digital model of the fingerprint, rather than just the central part of it.
Follow the instructions on the screen sequentially, if the system reports an error or asks you to repeat the action, just remove your finger and put it back on, slightly changing the angle, and after the circle is completed, the progress bar will fill in, and the fingerprint will be stored in the device memory.
Advanced sensitivity settings
After successfully saving your first print, MIUI offers improved recognition accuracy, especially if you wear gloves frequently or have dry hand skin, and select the profile you just created from the fingerprint management menu and click Add a fingerprint option.
Repeat the scanning procedure for the same finger, but this time try to apply it at different, sometimes sharper angles, which will expand the sensor's database and allow it to recognize your finger even with a imperfect touch, and the system may request to add several such options for one finger.
| Parameter | Description | Recommendation |
|---|---|---|
| Cushion center | Main scanning area | Scan first. |
| Finger edge | Side faces of the print | Add a second step |
| Fingertips | Top of the pad | Important for unlocking in your pocket |
| Ground | The bottom of the print. | Improves recognition when captured |
And you don't have to ignore this, because it's a big part of how fast the sensor works in your everyday life, and the calibration of the touch makes it much more comfortable to use your smartphone, and you'll notice that the number of false failures to unlock will be minimized.
Why can't the scanner see the finger after setting up?
Use of a fingerprint for other functions
The biometric data on Xiaomi Redmi 3S can be used not only for login, but also in the scanner settings, the “Use of fingerprint” section is available, which lists all the available application scenarios, which allows you to turn the sensor into a multifunctional control tool.
One of the most useful features is app authentication, and many banking clients, messengers like Telegram or WhatsApp, and photo storages support fingerprint login, so you don't have to type in long passwords every time you access sensitive information.
- 📸 Quick camera start: double tap on the screen turned off.
- 📞 Answer to incoming call: touching the sensor.
- 📂 Hiding Files: Access to a Hidden Folder in the Gallery.
- 🔒 Application Blocking: Entry into Individual Programs.
These functions are activated by simply switching the appropriate switches to the settings menu. Please note that some functions, such as hiding files, may require an additional password space, which creates a double layer of data protection.
Also worth noting is the Guest Mode feature, which allows you to set your smartphone so that when you unlock a certain finger (for example, with your right thumb), the main profile opens, and when you touch the other finger (for example, with your index left hand), you can set the guest mode with limited access.
Resolving problems and failures
Despite the reliability of the hardware part of the Redmi 3S, users may experience software failures in the scanner. If the sensor has stopped responding or has begun to make frequent errors, the first thing to do is to check the cleanliness of the surface.
⚠️ Warning: If the sensor stops working after falling or getting moisture, do not try to dry it with a hair dryer or heat it.
Software-wise, it helps to reboot the device. Sometimes the biometrics services can freeze in the background. Restarting the system resets these processes and restores the module to normal operation. Also check for system updates in the About Phone menu.
If the problem persists, try to delete all the saved prints and register them again. Sometimes the fingerprint database can get damaged and fresh calibration resolves the issue. Make sure that the phone does not have third-party themes or launchers that conflict with system security features.
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In 90% of cases, scanner problems are solved by cleaning the sensor and re-registering fingerprints with a change in the angle of the finger.