How to use a compass on your phone Xiaomi Redmi 9: a complete guide with tips and life hacks

Why you need a compass in a smartphone and how it works on Redmi 9

Modern smartphones, including the Xiaomi Redmi 9, have many sensors that users often don't even know exist, one of which is a magnetic compass built into an accelerometer/gyroscope chip that allows you to identify points of view to a few degrees without requiring an Internet connection or GPS. It is an indispensable tool for tourists, fishermen, hunters or just for navigating in unfamiliar terrain.

Unlike the classic compass with an arrow, the digital counterpart in Redmi 9 uses data from a magnetometer that interacts with the Earth's magnetic field. However, many owners face problems: the arrow twitches, the readings get lost or the application doesn't work at all. The reason most often lies in the wrong calibration of the sensor or interference from metal objects. In this article, we will discuss how to avoid typical errors and use the compass with maximum accuracy.

It's important to understand that the compass in a smartphone is not just an application, but a complex interaction of hardware (MIUI + hardware) and the software layer, so it requires not only the right setup to work properly, but also the external factors that we'll talk about later.

How to turn on a compass on Xiaomi Redmi 9: step-by-step instructions

Redmi 9 has a compass integrated into the standard Compass app, but it's not always easy to find it, especially if you've never used it.

1. Open the app menu (swipe up from the bottom edge of the screen).
2. Find the Compass icon (blue arrow on white background) and if it's not there, go to 3.
3. If the app is not available, download it from Google Play (e.g., Compass 360 Pro or Digital Compass).
4. Launch the app and wait for the smartphone to determine your location (access to geodata and sensors may be required when you first start up).

If the compass needle rotates randomly or shows the wrong direction after starting, it signals the need for calibration. More on this in the next section.

Calibration of the compass: why the arrow twitches and how to fix it

The most common problem with using a compass on Redmi 9 is the unstable reading of the arrow.

• 🧲 Influences of metal objects (keys, coins, magnet case).
• 📱 Sensor calibration violations after phone drop or update MIUI.
• 🔋 Electromagnetic interference from other devices (headphones, powerbank).
• 🌍 Locations in the magnetic anomalies zone (e.g., near power lines).

To calibrate the compass:

1. Open the Compass app.
2. If a “Low Accuracy” or “Calibration Required” notification appears, follow the prompts on the screen.
3. Rotate the phone in the air, describing the infinity sign (∞) until the accuracy scale is full.
4. Repeat the procedure 2-3 times for better results.

Make sure there are no metal objects nearby.|

Remove the magnetically attached case |

Turn off Bluetooth headphones or smartwatches |

Find an open space (not indoors!)-->

If calibration doesn’t help, try resetting the sensor settings:

1. Go to Settings → About the phone → All the parameters.
2. Find Reset Sensor Settings (or Sensor Calibration in Global Firmware).
3. Confirm the reset and restart the phone.

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If the compass is still not working properly, check the phone for physical damage, and a fall from a height can displace the magnetometer inside the case.

Top.-5 Compass applications for Xiaomi Redmi 9: better than standard

The standard Compass application in MIUI is often criticized for its minimalist functionality. If you need additional features - for example, maps with a compass link, recording routes or night mode - consider alternatives:

If you need a hiking compass, look for Azimuth and Compass or GPS Status, which allows you to save coordinates and build routes. Compass 360 Pro is enough for everyday use.

Errors and problems: why the compass on Redmi 9 lies

Even after calibration, the compass can produce incorrect data, and let's look at typical situations and solutions.

⚠️ Warning: If the phone was near a strong magnet (such as a speaker or induction stove), the sensor could be magnetized.

• 🔄 The arrow spins chaotically → Check for metal objects nearby or restart your phone.
• 📵 Compass doesn't respond to movement → Update. MIUI Up to the latest version or reset the sensor settings.
• 🌐 The readings get lost when the screen is turned. → Turn off autoturn in the display settings.
• 🔋 The compass only works when connected to charging → Possible problem with sensor power (diagnosis required).

If none of these things worked, it could be a hardware malfunction.

1. Check the compass through the engineering menu (enter ##4636## and select Sensor Test).
2. If the sensor is not responding, contact the Xiaomi service center.

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Before going to the service, check if the compass is turned off in the battery saving settings. To do this, go to Settings → Battery → Energy Saving Mode → Settings → Background Restrictions and make sure that the compass application is not blocked.

How to use a compass without the Internet: offline modes and maps

One of the key benefits of a digital compass is that it's not connected to the network, but you'll need offline maps to be fully navigated. Here's how to prepare them:

1. Install the Google Maps or Osmand app.
2. In Google Maps: Open menus → Offline maps. Select an area and download it. Enable compass mode (twice tap the blue dot of your location).

Osmand

• Download maps of regions through Settings → Maps.
• Activate the Compass plugin in the settings.

For maximum accuracy:

• 📍 Save key route points in advance (e.g. camp, water source).
• 🔦 Use a compass with a stopwatch to calculate the distance traveled (average pedestrian speed is 5 km / h).
• 🌲 Orient by the sun: in the northern hemisphere at noon it is in the south.

Remember, the compass shows magnetic north, which can vary by several degrees from geographic north (depending on the region), a difference called magnetic declination, and is usually shown on topographic maps.

Hidden Compass Features on Redmi 9: What You Didn't Know

Few people know that the compass in the Xiaomi Redmi 9 can be used for more than just orientation.

• 📱 In some applications (such as Sensor Box), the compass works together with the accelerometer, showing the angle of inclination of the phone.
• 🎮 Supported games AR: The compass is used in games like "Pokémon GO" or "Ingress" to determine the direction of movement.
• 📡 Finding sources of interference: If the compass needle behaves chaoticly, this may indicate hidden metal objects in the walls (for example, rebar or wiring).
• 🌌 Astronomical observations: With the help of a compass and the Star Walk application, you can find constellations knowing their azimuth.

Another useful feature is the binding of the compass to the camera, for example, in the Camera MX app you can turn on the display of the direction of shooting (useful for panoramic photos or drone video).

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If you use a compass often, add its widget to the home screen. To do this, click on the free screen space → Widgets → find the Compass and drag it.

FAQ: answers to frequent questions about the compass on Xiaomi Redmi 9