Sensor test: gyroscope, accelerometer and compass

Screen no longer rotating, navigation pointing the wrong way? This test shows your motion sensors' raw data in real time.

What the values mean

• alpha – compass heading (0–360°), changes as you rotate the phone around its vertical axis.
• beta – forward/backward tilt.
• gamma – left/right tilt.
• accel x/y/z – acceleration including gravity. At rest on a table, the z-axis should read about 9.8 m/s² – Earth's gravity, and the best quick sign that the accelerometer measures correctly.

Healthy looks like: steady values at rest, smooth changes in motion, the spirit-level dot following your hand without lag. Suspicious: frozen values, wild jumps without movement, or one axis stuck at 0 or a fixed number.

Everyday symptoms

A faulty or miscalibrated sensor shows up as: screen no longer auto-rotating, the maps app not knowing which way you're facing, distorted panorama photos, drifting tilt controls in games. Check the rotation lock first – it's by far the most common reason for "my screen stopped rotating" and takes seconds to fix.

Calibrate before you repair

The compass (magnetometer) is sensitive to magnetic interference: cases with magnetic clasps, car mounts and metal tables distort alpha readings massively – that's not a malfunction. Calibrate by moving the phone in a figure-eight a few times. True hardware failures of motion sensors are rare; when they happen (usually after a hard drop), the sensors sit on the mainboard and repair is rarely economical.