diff options
| -rw-r--r-- | include/hardware/sensors.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h index fb83c3f..9c2aa2a 100644 --- a/include/hardware/sensors.h +++ b/include/hardware/sensors.h @@ -268,6 +268,18 @@ __BEGIN_DECLS * Elements of the rotation vector are unitless. The x, y, and z axis are defined * in the same was as for the acceleration sensor. * + * The reference coordinate system is defined as a direct orthonormal basis, + * where: + * + * - X is defined as the vector product Y.Z (It is tangential to + * the ground at the device's current location and roughly points East). + * + * - Y is tangential to the ground at the device's current location and + * points towards the magnetic North Pole. + * + * - Z points towards the sky and is perpendicular to the ground. + * + * * The rotation-vector is stored as: * * sensors_event_t.data[0] = x*sin(theta/2) |