Android

The rotation sensor measures the orientation of the device as a combination of an angle and an axis, in which the device has rotated through an angle θ around an axis (x, y, or z). The rotational vector sensor is particularly versatile and can be used for a wide range of motion-related tasks, such as detecting gestures, monitoring angular change, and monitoring relative orientation changes. For example, the rotational vector sensor is ideal if you are developing a game, an augmented reality application, a 2-dimensional or 3-dimensional compass, or a camera stabilization app.

Three elements of the rotation vector are expressed as follows:

x*sin(θ/2)
y*sin(θ/2)
z*sin(θ/2)

Where the magnitude of the rotation vector is equal to sin(θ/2), and the direction of the rotation vector is equal to the direction of the axis of rotation. The three elements of the rotation vector are equal to the last three components of a unit quaternion (cos(θ/2), x*sin(θ/2), y*sin(θ/2), z*sin(θ/2)). Elements of the rotation vector are unitless. The x, y, and z axes are defined in the same way as the acceleration sensor. The reference coordinate system is defined as a direct orthonormal basis, seen above.

This coordinate system has the following characteristics:

X is defined as the vector product Y x Z. It is tangential to the ground at the device’s current location and points approximately East;
Y is tangential to the ground at the device’s current location and points toward the geomagnetic North Pole;
Z points toward the sky and is perpendicular to the ground plane.

For more information, check the official Android’s Sensor Coordinate System documentation.

Public functions

Rotation.getFrequency( Context context ): returns the sampling rate in Hz.

Settings

Aware_Preferences.STATUS_ROTATION: true or false to activate or deactivate sensor.
Aware_Preferences.FREQUENCY_ROTATION: non-deterministic frequency in microseconds (dependent of the hardware sensor capabilities and resources), e.g., 200000 (normal), 60000 (UI), 20000 (game), 0 (fastest).

Rotation.ACTION_AWARE_ROTATION: broadcasted when new data exists in Context Provider.
- Rotation.EXTRA_DATA: the inserted data, as ContentValues.
Rotation.ACTION_AWARE_ROTATION_LABEL: assign label to the recorded data.
- Rotation.EXTRA_LABEL: the desired label.

Rotation Sensor

Contains the hardware sensor capabilities in the mobile device.

Rotation_Sensor.CONTENT_URI
content://com.aware.provider.rotation/sensor_rotation

Table field	Field type	Description
_id	INTEGER	primary key, auto incremented
timestamp	REAL	unixtime milliseconds since 1970
device_id	TEXT	AWARE device UUID
double_sensor_maximum_range	REAL	Maximum sensor value possible
double_sensor_minimum_delay	REAL	Minimum sampling delay in microseconds
sensor_name	TEXT	Sensor’s name
double_sensor_power_ma	REAL	Sensor’s power drain in mA
double_sensor_resolution	REAL	Sensor’s resolution in sensor’s units
sensor_type	TEXT	Sensor’s type
sensor_vendor	TEXT	Sensor’s manufacturer
sensor_version	TEXT	Sensor’s version number

Rotation Data

Rotation_Data.CONTENT_URI
content://com.aware.provider.rotation/rotation

Table field	Field type	Description
_id	INTEGER	primary key, auto incremented
timestamp	REAL	unixtime milliseconds since 1970
device_id	TEXT	AWARE device UUID
double_values_0	REAL	the rotation vector component along the x axis, x*sin(θ/2)
double_values_1	REAL	the rotation vector component along the y axis, y*sin(θ/2)
double_values_2	REAL	the rotation vector component along the z axis, z*sin(θ/2)
double_values_3	REAL	cos(θ/2) (optional, manufacturer dependent)
accuracy	INTEGER	Sensor’s accuracy level (see SensorManager)
label	TEXT	Customizable label. Useful for data calibration or traceability

iOS

Rotation