iOS Guides | Samples

CoreMotion Namespace

The CoreMotion namespace provides access to motion data, including device acceleration and orientation, altitude, compass, and pedometer.


The CoreMotion API allows developers to get hardware events from the built-in accelerometer and gyroscopes.


CMAccelerationA 3D vector containing acceleration values.
CMAccelerometerDataAn accelerometer event, encapsulates an instance of CMAcceleration
CMAccelerometerHandlerA delegate signature used to receive events from CMMotionManager
CMAltimeterInterface to the relative-altitude pressure sensor.
CMAltitudeDataHolds relative-altitude data, generated by the CMAltitude class.
CMAttitudeUsed to pull spacial information from the device in either quaternion, rotation matrix or with 3D angles (roll, pitch and yaw).
CMAttitudeReferenceFrameAn enumeration whose values specify the reference frame from which CMAttitude readings are referenced.
CMCalibratedMagneticFieldEncapsulates the accuracy and field strength of the magnetometer after calibration.
CMDeviceMotionEncapsulates Attitude, Rotation Rate and Acceleration of the device.
CMDeviceMotionHandlerA delegate signature used to receive events from CMMotionManager
CMErrorType for CoreMotion errors.
CMGyroDataA single measurement of the device rotation rate.
CMGyroHandlerA delegate signature used to receive events from CMMotionManager
CMLogItemBase class for CMAccelerometerData, CMDeviceMotion and CMGyroData, it is used to attach a timestamp to these events.
CMMagneticFieldRepresents the 3-axis magnetometer data in microteslas.
CMMagneticFieldCalibrationAccuracyAn enumeration whose values specify the quality of the magnetometer calibration.
CMMagnetometerDataA reading from the device magnetometer.
CMMagnetometerHandlerA delegate that is the handler for the CMMotionManager.StartMagnetometerUpdates method.
CMMotionActivityA motion update event, including characterization of the likely form (walking, running, automotive).
CMMotionActivityConfidenceAn enumeration whose values specify the confidence in a CMMotionActivity.
CMMotionActivityHandlerThe delegate that acts as the handler for CMMotionActivityManager.QueryActivity.
CMMotionActivityManagerOn supported devices, accesses stored motion data and allows monitoring of motion updates.
CMMotionActivityQueryHandlerThe delegate that is the handler for CMMotionActivityManager.StartActivityUpdates.
CMMotionManagerCore class that provides access to the motion services in iOS.
CMPedometerGenerates step-counting data, including number of steps and floors climbed/descended.
CMPedometerDataHolds data relating to walking and floor-climbing. Generated by CMPedometer.
CMQuaternionRepresents a Quaternion, used as one of the possible CMAttitude representations.
CMRecordedAccelerometerDataAccelerometer data stored by a CMSensorRecorder.
CMRotationMatrixRepresents a 3x3 rotation matrix.
CMRotationRate3D rotation rate.
CMSensorDataListA system-provided list of objects that contain recorded Core Motion accelerometer data.
CMSensorRecorderGathers and retrieves accelerometer data.
CMStepCounterOn supported devices, stores the number of steps the user has taken with the device and allows step-counting to be dynamically tracked.
CMStepQueryHandlerThe delegate for use with CMStepCounter.QueryStepCount.
CMStepUpdateHandlerThe delegate used with CMStepCounter.StartStepCountingUpdates.