sensor_event_t

Structure to store information about a sensor event, which is obtained during a read.

Synopsis:

typedef struct  {
    size_t size ;
    sensor_type_e type ;
    uint32_t flags ;
    sensor_accuracy_e accuracy ;
    uint64_t timestamp ;
    union {
        struct {
            struct {
                float x, y, z;
            } dsp, raw;
            union {
                struct {
                    float temperature;
                } gyro;
            };
        } motion;
        float raw_data [18];
        float rotation_matrix [3*3];
        struct {
            int screen;
            char face [64];
        } orientation;
        struct {
            float azimuth;
            float pitch;
            float roll;
        } apr;
        struct {
            float distance;
            float normalized;
        } proximity_s;
        struct {
            float pressure;
            float temperature;
        } pressure_s;
        struct {
            float altitude ;
        } altitude_s;
        struct {
            float illuminance;
        } light_s;
        struct {
            int face_detect;
        } face_detect_s;
        struct {
            float temperature;
        } temperature_s;
        struct {
            int holstered;
        } holster_s;
        struct {
            float azimuth;
            int is_face_down;
        } compass_s;

        /** The following entries are deprecated; use the structures above, instead: **/
        float proximity;
        float pressure;
        float altitude;
        float illuminance;
        int face_detect;
        float temperature;
        struct {
            float x,y,x;
            struct {
                float x,y,z;
            } raw;
        } axis_s;
    };
}sensor_event_t;

Data:

size_t size
The size of this structure, which you can use to determine the version of the library you're using.
sensor_type_e type
The sensor type, used to index into appropriate payload.
uint32_t flags
Flags.
sensor_accuracy_e accuracy
The accuracy associated with this sample.
uint64_t timestamp
Time stamp of data acquisition, value in nanoseconds.
float raw_data
Misc bucket for data payload.
float rotation_matrix
Rotation Matrix.
struct motion
Used by motion sensors such as Accelerometer, Magnetometer, Gyroscope, Linear Acceleration and Gravity. The units of measure for the x, y and z values are as follows:
  • Accelerometer, Linear Acceleration, Gravity: m/s/s (meters/second/second)
  • Magnetometer: uT (micro Tesla)
  • Gyroscope: r/s (radians/second)
float x
x-value of the sensor.
float y
y-value of the sensor.
float z
z-value of the sensor.
dsp
Signal-processed/calibrated values.
raw
Raw sensor values.
float gyro.temperature
The temperature of the gyroscope sensor (in degrees Celsius).
struct orientation
Used by the orientation sensor.
int screen
Screen rotation in degrees: 0, 90, 180 or 270.
char face
String-based representation of device face. This is one of:
  • LEFT_UP
  • RIGHT_UP
  • TOP_UP
  • BOTTOM_UP
  • FACE_UP
  • FACE_DOWN
struct apr
Used by the azimuth/pitch/roll sensor.
float azimuth
0 to 359 degrees.

Azimuth from 0 -> 359 degrees from magnetic north.

float pitch
-180 to 180 degrees.
float roll
-90 to 90 degrees.
struct proximity_s
Used by the proximity sensor.
float distance
range_min -> range_max, discrete steps of distance or actual value in cm.
float normalized
0.0 -> 1.0 (close -> far), normalized unit-less signal from raw sensor.
struct pressure_s
Used by the pressure sensor.
float pressure
Pressure in pascals (Pa).
float temperature
Temperature in degrees Celsius.
struct altitude_s
Used by altitude sensor.
float altitude
Altitude (in meters) relative to mean sea level.
struct light_s
Used by the light sensor.
float illuminance
Illuminance in lux.
struct face_detect_s
Used by the face-detection sensor.
int face_detect
1 if a face is detected, 0 otherwise.
struct temperature_s
Used by the temperature sensor.
float temperature
Temperature in degrees Celsius.
struct holster_s
Used by the holster sensor.
int holstered
Holster status. 0 for not holstered, 1 for holstered.
struct compass_s
Used by the compass sensor.
int is_face_down
1 if the device's face is down and compass heading is flipped, 0 otherwise.
float azimuth
0 to 359 degrees.

Azimuth from 0 -> 359 degrees from magnetic north.

Deprecated variables
Use the structures above instead of the following deprecated items:
float proximity
Use proximity_s.distance instead.
float pressure
Use pressure_s.pressure instead.
float altitude
Use altitude_s.altitude instead.
float illuminance
Use light_s.illuminance instead.
int face_detect
Use face_detect_s.face_detect instead.
float temperature
Use temperature_s.temperature instead.
axis_s: float x,y,z; axis.raw: float x,y,z
Use motion instead.

Library:

None.

Description:

Note that only one section of the union is used for any event. For example, when a SENSOR_TYPE_COMPASS event occurs, the compass_s is populated with the event data.

Last modified: 2013-12-21

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