A smartphone sensor is any one of a number of different types of sensing devices installed on a user's phone to gather data for various user purposes, often in conjunction with a mobile app.
- An accelerometer detects acceleration, tilt and vibration to determine movement and orientation.
- A gyroscope identifies up/down, left/right and rotation around three axes for more complex orientation details.
- A light sensor detects data about lighting levels in the environment to adapt the display accordingly.
- A proximity sensor detects when the the phone is held to the face to make or take a call, so the touch screen display can be disabled to avoid unintended input.
- A fingerprint sensor can enable biometric verification for secure device and website authentication as well as mobile payment.
- A magnetometer detects the direction of magnetic north and, in conjunction with GPS, determines the user's location.
- An infrared sensor can be used to identify user movements for gesture recognition.
In this video, Engineer Guy takes a smartphone apart and explains how the accelerometer works. He also shares the essential idea underlying the micro-electromechanical systems (MEMS) production of these devices: