CMMotionActivity

On iOS and watchOS, CMMotionActivityManager takes raw sensor data from the device and tells you (to what degree of certainty) whether the user is currently moving, and if they’re walking, running, biking, or driving in an automobile.

→ nshipster.com/cmmotionactivity/

The Core Motion framework’s CMMotionActivityManager on iOS and watchOS uses a device’s motion coprocessor to process sensor data from accelerometers, gyroscopes, and magnetometers, determining user activities like walking, running, cycling, automotive travel, or being stationary with varying confidence levels.

By creating a single CMMotionActivityManager instance and using startActivityUpdates(to:withHandler:), developers can receive CMMotionActivity objects that indicate motion states, which are not mutually exclusive, allowing scenarios like a stationary car at a red light to register both automotive and stationary.

The API, introduced with the M7 coprocessor in iPhone 5S and iOS 7, supports features like “Do Not Disturb While Driving” by leveraging sensor fusion, possibly using magnetometer data to detect vehicle environments. Combining motion data with Core Location can enhance accuracy, such as distinguishing swimming from boating, but location use should be minimised due to high energy consumption.

Developers are encouraged to test confidence levels empirically and explore Core Motion’s capabilities to create responsive, immersive apps using Swift’s clear syntax and safety features.