CMAltimeter¶

Reports relative and (iOS 15+) absolute altitude from the device barometer.

Description¶

Wraps Apple’s CMAltimeter. Use start_relative_altitude_updates() for change-from-start readings and start_absolute_altitude_updates() for sea-level-referenced readings (iOS 15+).

Requires the ``NSMotionUsageDescription`` Info.plist key.

Platform availability: Real implementation on iOS. On other platforms is_*_available returns false and calls to start updates emit altimeter_failed.

See Apple’s CMAltimeter reference.

Tutorials¶

CoreMotion Integration Guide

Methods¶

int	authorization_status() static
bool	is_absolute_altitude_available() static
bool	is_relative_altitude_available() static
void	start_absolute_altitude_updates()
void	start_relative_altitude_updates()
void	stop_absolute_altitude_updates()
void	stop_relative_altitude_updates()

Signals¶

absolute_altitude_updated(altitude: CMAbsoluteAltitudeData) 🔗

Emitted on the main thread when a new absolute altitude sample is available.

altimeter_failed(message: String) 🔗

Emitted when CoreMotion reports an error or when the API is unavailable on the current platform.

relative_altitude_updated(altitude: CMAltitudeData) 🔗

Emitted on the main thread when a new relative altitude sample is available.

Method Descriptions¶

int authorization_status() static 🔗

Returns Apple’s CMAuthorizationStatus integer for altimeter access (0 = notDetermined, 1 = restricted, 2 = denied, 3 = authorized).

bool is_absolute_altitude_available() static 🔗

Returns true when the device can report absolute (sea-level) altitude. Requires iOS 15 or later.

bool is_relative_altitude_available() static 🔗

Returns true when the device has a barometer capable of reporting relative altitude.

void start_absolute_altitude_updates() 🔗

Begins absolute altitude updates delivered via absolute_altitude_updated. iOS 15+; emits altimeter_failed on earlier iOS versions or other platforms.

void start_relative_altitude_updates() 🔗

Begins relative altitude updates delivered via relative_altitude_updated.

void stop_absolute_altitude_updates() 🔗

Stops absolute altitude updates.

void stop_relative_altitude_updates() 🔗

Stops relative altitude updates.