How to check the presence of a magnetic sensor in a Xiaomi smartphone

Many Xiaomi, Redmi and POCO smartphone owners are wondering if they have a magnetic sensor, or magnetometer, in their device, which is critical not only for navigation maps, but also for using a compass, as well as for automatically calibrating the screen when turning the device. Often users buy magnetic-clasp cases or plan to attach the phone to the car without knowing whether the electronics will withstand such a neighborhood or whether there is protection from magnetic fields at all.

Checking for a magnetic sensor is a simple procedure, but it requires care, because software methods can fail. In current models of the budget and mid-size segments, manufacturers sometimes save on individual components, relying on software emulation or gyroscope data. However, for a full-fledged navigation in pedestrian mode or in the forest, the presence of a hardware magnetometer is necessary.

In this article, we will look at all the diagnostic tools available, from built-in MIUI and HyperOS to the use of specialized utilities, learn how to distinguish software simulations from real equipment and understand how to properly calibrate the sensor if it is detected, this knowledge will help avoid problems with orientation in the ground and ensure that all the functions of the smartphone work correctly.

Why you need a magnetometer in a modern smartphone

A magnetic sensor, or magnetometer, acts as a digital compass, determining the direction of the cardinal points relative to the Earth's magnetic field. Without this component, navigation applications like Google Maps or Yandex.Navigator can show your location, but they won't know which way you're looking, which is especially important for pedestrians who need to navigate quickly at an intersection or in an unfamiliar area.

In addition to navigation, the magnetic field sensor is used in various utilities and augmented reality games. For example, applications for finding hidden wiring or metal detectors work solely by reading changes in the magnetic background. Some smart cases use a magnet to activate the screen, and the sensor helps the phone to understand whether it is closed or open, although this is more often responsible for a separate Hall sensor.

It's important to understand the difference between a gyroscope and a magnetometer. A gyroscope tracks the device's rotations in space, but it doesn't know where north is, and a magnetometer gives absolute binding to the cardinal points. In conjunction, these two components provide precise positioning. If your Xiaomi doesn't have a magnetic sensor, the compass in the navigator will not work properly or require constant manual adjustment.

Checking through CIT's engineering menu

The most reliable way to check for hardware is to use the built-in CIT (Component Integration Test) menu, a hidden part of the system designed to test all smartphone modules in the factory, accessed through a special code in the Phone app.

To enter, open the dialer and dial the combination ##6484##. If the code is entered correctly, the test menu will open. In the list of parameters, you will find the item associated with the magnetometer. It can be called Magnetometer, Compass or Sensor. By clicking on it, you will be in test mode, where the current readings of the sensor in microteslas (uT) will be displayed on the screen.

⚠️ Note: If the menu does not open when you enter the code, it is possible that your firmware version will be MIUI Or HyperOS blocks this method, so try the code ##64663##, which sometimes works on older models.

In the test mode, you'll see three coordinate axes (X, Y, Z). When you turn the phone, the values should change. If the values are static or zero, the sensor is either missing or defective. Also, there's often a calibration feature available in this menu, which is useful to start before the main check.

Use of third-party applications for diagnosis

If you have no access to the engineering menu or want more technical information, the best way to use specialized applications from Google Play is to use the CPU-Z utility or Sensor Box for Android, which reads data directly from the system registry of devices.

Once you install and start the CPU-Z, go to the Sensors tab, and here's a complete list of all the sensors that the system sees in the machine. Look for the "Magnetic Field" or "Magnetometer" line. If there's no such string, then the hardware magnetometer in the phone is physically missing, and it emulates the software based on other data.

Another useful application is GPS Status & Toolbox, which not only shows satellites, but also has an embedded A-GPS data tool with a compass calibration button, and if you try to calibrate it, the app says that the sensor is not found, or the compass needle twitches randomly without reacting to turns, this is a sure sign of the module's absence or breakdown.

Testing with a physical magnet

There's a "old-fashioned" but highly effective test method that doesn't require software installation, which requires any neodymium magnet or magnetic clasp from the case, and the essence of the method is to react a screen or an audio signal to a magnetic field.

Turn on any compass app on your smartphone or run a test in the engineering menu. Hold the magnet to the top of the case (where the front camera and speaker are usually located) and slowly guide it along the screen. If there is a sensor, the values on the screen should change dramatically, and the compass needle should deviate towards the magnet.

However, be careful: too powerful a magnet can damage the camera's optics or other senses of the athletic elements.

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Use a weak magnet from a bookcase for the test. Powerful neodymium magnets can demagnetize the speaker or disrupt the camera stabilizer.

Table of the presence of sensors in popular series

To be sure, you can look at the statistics of different smartphone lines. Of course, there may be different revisions within the same model, but the general trend is clear. Flagships are almost always full set, and in public sector employees there are often simplifications.

As you can see from the table, in the budget models of the Redmi series (without the Note console) and the POCO M, manufacturers often remove the magnetometer to reduce the cost. In such phones, the navigator shows the blue dot, but does not show the sector of the direction of travel until you start moving at a certain speed.

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The lack of a magnetometer in budget models is a normal practice of saving money, but it makes it impossible to use the phone as a full-fledged compass without movement.

Problems and calibration of the magnetic sensor

Even if the sensor is present, it may not work properly, and a common problem is the "swimming" of readings or the inability to calibrate the compass, which happens after a fall, a change in the screen (if low-quality parts with magnets were used), or an proximity sensor.

To calibrate in MIUI, it is often enough to spin the phone several times in the air, drawing an eight. If this does not help, you can use third-party calibrators. But if this does not work, it is possible that the sensor is software disabled or the train is damaged.

Also affected by the metal case or magnetic mount in the car. If the needle of the compass behaves strangely, try to remove the case and remove the phone from the sources of magnetic fields (columns, chargers, other phones).

What to do if the sensor is missing or broken

If you find out that your Xiaomi doesn't have a magnetic sensor, and you need one (for hiking, for example), you can't software add it. It's a physical component that needs to be soldered on the board. The only way out is to use an external Bluetooth compass that connects to the phone.

In case of a breakdown (the sensor was but stopped responding), it's worth checking if you've recently installed a custom firmware or core that may not have drivers for your sensor.

If the problem is hardware, repairs are only possible in a service center where the module is replaced or the chip is soldered, but the cost of such repairs for budget models is often impractical.