2 * Copyright (C) 2008 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_SENSORS_INTERFACE_H
18 #define ANDROID_SENSORS_INTERFACE_H
21 #include <sys/cdefs.h>
22 #include <sys/types.h>
24 #include <hardware/hardware.h>
25 #include <cutils/native_handle.h>
30 * The id of this module
32 #define SENSORS_HARDWARE_MODULE_ID "sensors"
35 * Name of the sensors device to open
37 #define SENSORS_HARDWARE_POLL "poll"
40 * Handles must be higher than SENSORS_HANDLE_BASE and must be unique.
41 * A Handle identifies a given sensors. The handle is used to activate
42 * and/or deactivate sensors.
43 * In this version of the API there can only be 256 handles.
45 #define SENSORS_HANDLE_BASE 0
46 #define SENSORS_HANDLE_BITS 8
47 #define SENSORS_HANDLE_COUNT (1<<SENSORS_HANDLE_BITS)
53 #define SENSOR_TYPE_ACCELEROMETER 1
54 #define SENSOR_TYPE_MAGNETIC_FIELD 2
55 #define SENSOR_TYPE_ORIENTATION 3
56 #define SENSOR_TYPE_GYROSCOPE 4
57 #define SENSOR_TYPE_LIGHT 5
58 #define SENSOR_TYPE_PRESSURE 6
59 #define SENSOR_TYPE_TEMPERATURE 7
60 #define SENSOR_TYPE_PROXIMITY 8
63 * Values returned by the accelerometer in various locations in the universe.
64 * all values are in SI units (m/s^2)
67 #define GRAVITY_SUN (275.0f)
68 #define GRAVITY_EARTH (9.80665f)
70 /** Maximum magnetic field on Earth's surface */
71 #define MAGNETIC_FIELD_EARTH_MAX (60.0f)
73 /** Minimum magnetic field on Earth's surface */
74 #define MAGNETIC_FIELD_EARTH_MIN (30.0f)
78 * status of each sensor
81 #define SENSOR_STATUS_UNRELIABLE 0
82 #define SENSOR_STATUS_ACCURACY_LOW 1
83 #define SENSOR_STATUS_ACCURACY_MEDIUM 2
84 #define SENSOR_STATUS_ACCURACY_HIGH 3
87 * Definition of the axis
88 * ----------------------
90 * This API is relative to the screen of the device in its default orientation,
91 * that is, if the device can be used in portrait or landscape, this API
92 * is only relative to the NATURAL orientation of the screen. In other words,
93 * the axis are not swapped when the device's screen orientation changes.
94 * Higher level services /may/ perform this transformation.
99 * +-----------+--> y>0
111 * |/ z>0 (toward the sky)
113 * O: Origin (x=0,y=0,z=0)
119 * All values are angles in degrees.
121 * Orientation sensors return sensor events for all 3 axes at a constant
122 * rate defined by setDelay().
124 * azimuth: angle between the magnetic north direction and the Y axis, around
125 * the Z axis (0<=azimuth<360).
126 * 0=North, 90=East, 180=South, 270=West
128 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when
129 * the z-axis moves toward the y-axis.
131 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when
132 * the x-axis moves towards the z-axis.
134 * Note: For historical reasons the roll angle is positive in the clockwise
135 * direction (mathematically speaking, it should be positive in the
136 * counter-clockwise direction):
142 * | | roll: rotation around Y axis
145 * note that +Y == -roll
149 * Note: This definition is different from yaw, pitch and roll used in aviation
150 * where the X axis is along the long side of the plane (tail to nose).
156 * All values are in SI units (m/s^2) and measure the acceleration of the
157 * device minus the force of gravity.
159 * Acceleration sensors return sensor events for all 3 axes at a constant
160 * rate defined by setDelay().
162 * x: Acceleration minus Gx on the x-axis
163 * y: Acceleration minus Gy on the y-axis
164 * z: Acceleration minus Gz on the z-axis
167 * When the device lies flat on a table and is pushed on its left side
168 * toward the right, the x acceleration value is positive.
170 * When the device lies flat on a table, the acceleration value is +9.81,
171 * which correspond to the acceleration of the device (0 m/s^2) minus the
172 * force of gravity (-9.81 m/s^2).
174 * When the device lies flat on a table and is pushed toward the sky, the
175 * acceleration value is greater than +9.81, which correspond to the
176 * acceleration of the device (+A m/s^2) minus the force of
177 * gravity (-9.81 m/s^2).
183 * All values are in micro-Tesla (uT) and measure the ambient magnetic
184 * field in the X, Y and Z axis.
186 * Magnetic Field sensors return sensor events for all 3 axes at a constant
187 * rate defined by setDelay().
192 * The distance value is measured in centimeters. Note that some proximity
193 * sensors only support a binary "close" or "far" measurement. In this case,
194 * the sensor should report its maxRange value in the "far" state and a value
195 * less than maxRange in the "near" state.
197 * Proximity sensors report a value only when it changes and each time the
198 * sensor is enabled. setDelay() is ignored.
203 * The light sensor value is returned in SI lux units.
205 * Light sensors report a value only when it changes and each time the
206 * sensor is enabled. setDelay() is ignored.
211 * The pressure sensor value is returned in hectopascal (hPa)
213 * Pressure sensors report events at a constant rate defined by setDelay().
218 * The gyroscope sensor values are returned in degrees per second (dps)
220 * Gyroscope sensor report events at a constant rate defined by setDelay().
242 * Union of the various types of sensor data
243 * that can be returned.
245 typedef struct sensors_event_t {
246 /* must be sizeof(struct sensors_event_t) */
249 /* sensor identifier */
258 /* time is in nanosecond */
264 /* acceleration values are in meter per second per second (m/s^2) */
265 sensors_vec_t acceleration;
267 /* magnetic vector values are in micro-Tesla (uT) */
268 sensors_vec_t magnetic;
270 /* orientation values are in degrees */
271 sensors_vec_t orientation;
273 /* angular velocity in degrees per second (dps) */
276 /* temperature is in degrees centigrade (Celsius) */
279 /* distance in centimeters */
282 /* light in SI lux units */
285 /* pressure in hectopascal (hPa) */
288 uint32_t reserved1[4];
296 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
297 * and the fields of this data structure must begin with hw_module_t
298 * followed by module specific information.
300 struct sensors_module_t {
301 struct hw_module_t common;
304 * Enumerate all available sensors. The list is returned in "list".
305 * @return number of sensors in the list
307 int (*get_sensors_list)(struct sensors_module_t* module,
308 struct sensor_t const** list);
312 /* name of this sensors */
314 /* vendor of the hardware part */
316 /* version of the hardware part + driver. The value of this field is
317 * left to the implementation and doesn't have to be monotonically
321 /* handle that identifies this sensors. This handle is used to activate
322 * and deactivate this sensor. The value of the handle must be 8 bits
323 * in this version of the API.
326 /* this sensor's type. */
328 /* maximaum range of this sensor's value in SI units */
330 /* smallest difference between two values reported by this sensor */
332 /* rough estimate of this sensor's power consumption in mA */
334 /* minimum delay allowed between events in microseconds. A value of zero
335 * means that this sensor doesn't report events at a constant rate, but
336 * rather only when a new data is available */
338 /* reserved fields, must be zero */
344 * Every device data structure must begin with hw_device_t
345 * followed by module specific public methods and attributes.
347 struct sensors_poll_device_t {
348 struct hw_device_t common;
350 /** Activate/deactivate one sensor.
352 * @param handle is the handle of the sensor to change.
353 * @param enabled set to 1 to enable, or 0 to disable the sensor.
355 * @return 0 on success, negative errno code otherwise
357 int (*activate)(struct sensors_poll_device_t *dev,
358 int handle, int enabled);
361 * Set the delay between sensor events in nanoseconds for a given sensor.
362 * It is an error to set a delay inferior to the value defined by
363 * sensor_t::minDelay. If sensor_t::minDelay is zero, setDelay() is
364 * ignored and returns 0.
366 * @return 0 if successful, < 0 on error
368 int (*setDelay)(struct sensors_poll_device_t *dev,
369 int handle, int64_t ns);
372 * Returns an array of sensor data.
373 * This function must block until events are available.
375 * @return the number of events read on success, or -errno in case of an error.
376 * This function should never return 0 (no event).
379 int (*poll)(struct sensors_poll_device_t *dev,
380 sensors_event_t* data, int count);
383 /** convenience API for opening and closing a device */
385 static inline int sensors_open(const struct hw_module_t* module,
386 struct sensors_poll_device_t** device) {
387 return module->methods->open(module,
388 SENSORS_HARDWARE_POLL, (struct hw_device_t**)device);
391 static inline int sensors_close(struct sensors_poll_device_t* device) {
392 return device->common.close(&device->common);
397 #include <hardware/sensors_deprecated.h>
399 #endif // ANDROID_SENSORS_INTERFACE_H