Fitness trackers often think about the privacy of their data, especially when the device is constantly on the wrist and displays notifications. Screen locking becomes not just a function, but a necessity for those who want to hide personal correspondence or health indicators from prying eyes. Xiaomi Mi Band 4 has a reliable protection system that is activated when removing the gadget from the hand.
The security setting process does not require complex technical knowledge, but it has its own features that not all users are aware of. It is important to understand that a password will be requested automatically every time sensors detect no contact with the skin. This clever behavior of the system provides a balance between usability and reliable protection of personal information.
In this article, we will discuss in detail all the steps of activation of the security code, possible problems in synchronization and the subtlety of the proximity sensors. You will learn how to make the use of your tracker as safe as possible without losing comfort in everyday operation.
The principle of protection and sensors
The fundamental safety feature of the Mi Band 4 is an optical pulse sensor that does a dual function: it not only reads biometrics, it also detects whether the wristband is on the wearer's wrist, and when you remove the device, the screen goes out, and when you put it on and activate it, the system checks for contact with the skin.
If the protection function is enabled, then instead of the usual dial, you will see a request for input. PIN-This happens as long as the tracker "feels" that it's off, and once the sensors confirm that it's on the hand, the lock is automatically removed, and the device goes into active operation.
It's worth noting that the algorithms for sensors can vary depending on the firmware version, and in some cases, you need a light touch of the screen or a wrist lift to initiate a password check, to save battery power and prevent false positives.
- 🔒 Automatic activation of protection when removing from hand.
- ⌚ Instant unlocking when confirming wearing on the wrist.
- 📉 Minimum impact on the autonomy of the device.
⚠️ Warning: Do not try to seal the pulse sensor with tape or tape in the hope of fooling the system, this will lead to incorrect measurement of the pulse and may disrupt the algorithms for determining the removal of the bracelet.
Preparation for security settings
Before you start setting your password, you need to make sure your software is up to date. An outdated version of the Mi Fit (or Zepp Life) app may not contain the necessary security modules or may not work properly with newer versions of the bracelet firmware. The update takes only a couple of minutes, but guarantees stability.
It is also important to check the battery level of the tracker itself. The adjustment process and the subsequent constant operation of the sensors in the wear monitoring mode require energy. If the charge is critically low, the system may not allow new functions to be turned on or warn you about the need to connect to the charger.
Make sure that Bluetooth on your smartphone is active and stable. Settings are synchronized in real time, and breaking the connection when you set the password can cause configuration failure.
☑️ Preparation for password setting
Besides technical training, you should come up with a memorizable code in advance, because you have to type it in quite often (every time after you remove it), it should not be too complicated, but obvious combinations like 1234 should not be used if you really care about privacy.
Step-by-step instruction: setting a password
The main process of activating protection is done exclusively through the mobile application. There is no password menu on the bracelet itself, all control commands come from the phone. Open the Mi Fit app and go to the Profile tab in the lower right corner of the screen.
In the list of connected devices, find your Mi Band 4 and click on it. You will see a detailed menu of tracker settings. Scroll down to the section "Bracelet settings" or "Screen lock." The exact name of the item may vary slightly depending on the version of the interface.
Activate the "Block Screen" switch. The system will prompt you to come up with a 4-digit switch. PIN-Enter it twice to confirm, and after you successfully enter the bracelet, you will notice that the protection is activated and you will need to enter the code once to confirm it.
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If you forget the set-up PIN-code, the only way to unlock the device will be a complete reset to factory settings through the application, which will result in the removal of all accumulated data.
After setting the password, the system will suggest adjusting the sensitivity or additional parameters, if they are available in your version of the software. It is recommended to immediately test the function: remove the bracelet, wait a couple of seconds until the screen goes out, and then put it on again and check the code request.
Set up unlocking by steps
For more detailed configuration of the device's lock behavior, refer to the advanced settings in the application, which can be found here, you can find options that affect the speed of sensor response and the waiting time before turning on the screen, and correct calibration of these parameters will eliminate delays.
The settings menu may also include the option “Unlock Password-Free When Wearing.” Make sure it’s active. This feature is responsible for ensuring that after the first successful password entry and confirmation of wear, the device does not request the code again until you remove it from your hand.
Some firmware versions allow you to adjust the autolock timer. You can choose how many seconds of inactivity the screen should go out and go into the waiting mode of the password. Short interval increases security, but can spend the battery more often on permanent turns.
| Parameter | Recommended value | Impact on work |
|---|---|---|
| Length PIN-code | 4 numbers | Standard of safety |
| Screen sleep timer | 10-15 sec. | Balance of convenience and energy |
| Sensitivity of the sensor | Tall. | Quick reaction to withdrawal |
| Vibrant response | Included. | Tactile input confirmation |
Notice the vibration when you enter the code. Tactile response helps you know that you have a click, which is especially important in low light or when you are in a hurry. It is not recommended to turn off this feature, as it improves the usability of the interface.
Features of working with notifications
Having a password on the screen directly affects how notifications are displayed. For security reasons, text messages, calls and reminders can be hidden until the device is unlocked.
This behavior can be configured in the Mi Fit notification section, where you can choose which apps will show previews of messages even on a locked screen and which will be completely hidden, allowing you to flexibly manage the flow of information.
Hiding the contents of messages
For example, a response to a call or a quick response to a message may require prior unlocking to prevent accidental tapping or unauthorized action.
- 📩 Hiding the text of messages before entering the code.
- 📞 Displaying the caller's name without restrictions (by default).
- 🔔 Vibration ability when the screen is locked.
This is especially useful in business environments or meetings where you don’t want private messages to be visible, adding another layer of privacy to your existing data protection.
Addressing problems and failures
One of the common problems is that the bracelet doesn't ask for a password after removing it, most often due to contamination of the optical sensor, sweat, dirt or greasy film can interfere with the correct reading of data, and the system "thinks" that the device is still on the hand.
Another reason may be that the Bluetooth connection is not working properly, and if the connection between the phone and the bracelet is unstable, the lock status may not be updated in time, try to disable and reconnect the device in the Bluetooth menu of the smartphone.
⚠️ Warning: If the bracelet is frozen or hit by extreme cold, the lithium battery and sensors may not work properly.
In rare cases, complete device reassignment helps: Remove the Mi Band 4 from the app, reset the bracelet settings (via the menu or by pressing a button if the model allows, but for Band 4 reset only through the app) and add it again as a new device.
Impact of protection on autonomy
Many users fear that the constant operation of sensors and the screen to check the password will significantly reduce battery life. In practice, the optimization in the Mi Band 4 is done very competently, the additional energy costs are less than 5-7% of the total consumption.
The main energy consumer is the AMOLED screen, but it is only activated for a short time to enter the code. The pulse sensor used to detect withdrawal is pulsed and does not require constant high power consumption.
If you notice that after you turn on the password, the bracelet begins to discharge noticeably faster, check other settings. You may have a constant backlight on the screen (Always On Display) or too high a pulse rate, which adds up to a load.
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Turning on the screen lock has little or no effect on the overall battery life of the Mi Band 4 thanks to efficient energy saving algorithms.
To maximize charge savings, you can reduce the brightness of the screen or reduce the time it burns in settings, which compensate for any minimal energy loss caused by the operation of the security system, allowing you to enjoy data protection without compromise.