diff options
| -rw-r--r-- | include/hardware/sensors.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h index 610651fc..61e411cc 100644 --- a/include/hardware/sensors.h +++ b/include/hardware/sensors.h @@ -59,6 +59,9 @@ __BEGIN_DECLS #define SENSOR_TYPE_PRESSURE 6 #define SENSOR_TYPE_TEMPERATURE 7 #define SENSOR_TYPE_PROXIMITY 8 +#define SENSOR_TYPE_GRAVITY 9 +#define SENSOR_TYPE_LINEAR_ACCELERATION 10 +#define SENSOR_TYPE_ROTATION_VECTOR 11 /** * Values returned by the accelerometer in various locations in the universe. @@ -189,6 +192,17 @@ __BEGIN_DECLS * All values are in micro-Tesla (uT) and measure the ambient magnetic * field in the X, Y and Z axis. * + * Gyroscope + * --------- + * All values are in radians/second and measure the rate of rotation + * around the X, Y and Z axis. The coordinate system is the same as is + * used for the acceleration sensor. Rotation is positive in the counter-clockwise + * direction. That is, an observer looking from some positive location on the x, y. + * or z axis at a device positioned on the origin would report positive rotation + * if the device appeared to be rotating counter clockwise. Note that this is the + * standard mathematical definition of positive rotation and does not agree with the + * definition of roll given earlier. + * * Proximity * --------- * @@ -202,7 +216,32 @@ __BEGIN_DECLS * * The light sensor value is returned in SI lux units. * + * Gravity + * ------- + * A gravity output indicates the direction of and magnitude of gravity in the devices's + * coordinates. On Earth, the magnitude is 9.8. Units are m/s^2. The coordinate system + * is the same as is used for the acceleration sensor. + * + * Linear Acceleration + * ------------------- + * Indicates the linear acceleration of the device in device coordinates, not including gravity. + * This output is essentially Acceleration - Gravity. Units are m/s^2. The coordinate system is + * the same as is used for the acceleration sensor. + * + * Rotation Vector + * --------------- + * A rotation vector represents the orientation of the device as a combination + * of an angle and an axis, in which the device has rotated through an angle + * theta around an axis <x, y, z>. The three elements of the rotation vector + * are <x*sin(theta/2), y*sin(theta/2), z*sin(theta/2)>, such that the magnitude + * of the rotation vector is equal to sin(theta/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(theta/2), x*sin(theta/2), y*sin(theta/2), z*sin(theta/2)>. + * Elements of the rotation vector are unitless. The x, y, and z axis are defined + * in the same was as for the acceleration sensor. */ + typedef struct { union { float v[3]; |