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The Android Open Source Projectf53ebec2009-03-03 19:32:14 -08001/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
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
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17#ifndef ANDROID_SENSORS_INTERFACE_H
18#define ANDROID_SENSORS_INTERFACE_H
19
20#include <stdint.h>
21#include <sys/cdefs.h>
22#include <sys/types.h>
23
24#include <hardware/hardware.h>
Mike Lockwood21b652f2009-05-22 10:05:48 -040025#include <cutils/native_handle.h>
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080026
27__BEGIN_DECLS
28
29/**
30 * The id of this module
31 */
32#define SENSORS_HARDWARE_MODULE_ID "sensors"
33
34/**
35 * Name of the sensors device to open
36 */
Mathias Agopianb1e212e2010-07-08 16:44:54 -070037#define SENSORS_HARDWARE_POLL "poll"
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080038
39/**
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.
44 */
45#define SENSORS_HANDLE_BASE 0
46#define SENSORS_HANDLE_BITS 8
47#define SENSORS_HANDLE_COUNT (1<<SENSORS_HANDLE_BITS)
48
49
50/**
51 * Sensor types
52 */
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
Kevin Powell4ec14c12010-07-19 19:12:15 -070061#define SENSOR_TYPE_GRAVITY 9
62#define SENSOR_TYPE_LINEAR_ACCELERATION 10
63#define SENSOR_TYPE_ROTATION_VECTOR 11
Urs Fleischd2ed15a2010-12-29 17:00:33 +010064#define SENSOR_TYPE_RELATIVE_HUMIDITY 12
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080065
66/**
67 * Values returned by the accelerometer in various locations in the universe.
68 * all values are in SI units (m/s^2)
69 */
70
71#define GRAVITY_SUN (275.0f)
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080072#define GRAVITY_EARTH (9.80665f)
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080073
74/** Maximum magnetic field on Earth's surface */
75#define MAGNETIC_FIELD_EARTH_MAX (60.0f)
76
77/** Minimum magnetic field on Earth's surface */
78#define MAGNETIC_FIELD_EARTH_MIN (30.0f)
79
80
81/**
82 * status of each sensor
83 */
84
85#define SENSOR_STATUS_UNRELIABLE 0
86#define SENSOR_STATUS_ACCURACY_LOW 1
87#define SENSOR_STATUS_ACCURACY_MEDIUM 2
88#define SENSOR_STATUS_ACCURACY_HIGH 3
89
90/**
91 * Definition of the axis
92 * ----------------------
93 *
94 * This API is relative to the screen of the device in its default orientation,
95 * that is, if the device can be used in portrait or landscape, this API
96 * is only relative to the NATURAL orientation of the screen. In other words,
97 * the axis are not swapped when the device's screen orientation changes.
98 * Higher level services /may/ perform this transformation.
99 *
100 * x<0 x>0
101 * ^
102 * |
103 * +-----------+--> y>0
104 * | |
105 * | |
106 * | |
107 * | | / z<0
108 * | | /
109 * | | /
110 * O-----------+/
111 * |[] [ ] []/
112 * +----------/+ y<0
113 * /
114 * /
115 * |/ z>0 (toward the sky)
116 *
117 * O: Origin (x=0,y=0,z=0)
118 *
119 *
120 * Orientation
121 * -----------
122 *
123 * All values are angles in degrees.
124 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700125 * Orientation sensors return sensor events for all 3 axes at a constant
126 * rate defined by setDelay().
127 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800128 * azimuth: angle between the magnetic north direction and the Y axis, around
129 * the Z axis (0<=azimuth<360).
130 * 0=North, 90=East, 180=South, 270=West
131 *
132 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when
133 * the z-axis moves toward the y-axis.
134 *
135 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when
Mathias Agopian19ea59f2010-02-26 13:15:18 -0800136 * the x-axis moves towards the z-axis.
137 *
138 * Note: For historical reasons the roll angle is positive in the clockwise
139 * direction (mathematically speaking, it should be positive in the
140 * counter-clockwise direction):
141 *
142 * Z
143 * ^
144 * (+roll) .--> |
145 * / |
146 * | | roll: rotation around Y axis
147 * X <-------(.)
148 * Y
149 * note that +Y == -roll
150 *
151 *
152 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800153 * Note: This definition is different from yaw, pitch and roll used in aviation
154 * where the X axis is along the long side of the plane (tail to nose).
155 *
156 *
157 * Acceleration
158 * ------------
159 *
160 * All values are in SI units (m/s^2) and measure the acceleration of the
161 * device minus the force of gravity.
162 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700163 * Acceleration sensors return sensor events for all 3 axes at a constant
164 * rate defined by setDelay().
165 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800166 * x: Acceleration minus Gx on the x-axis
167 * y: Acceleration minus Gy on the y-axis
168 * z: Acceleration minus Gz on the z-axis
169 *
170 * Examples:
171 * When the device lies flat on a table and is pushed on its left side
172 * toward the right, the x acceleration value is positive.
173 *
174 * When the device lies flat on a table, the acceleration value is +9.81,
175 * which correspond to the acceleration of the device (0 m/s^2) minus the
176 * force of gravity (-9.81 m/s^2).
177 *
178 * When the device lies flat on a table and is pushed toward the sky, the
179 * acceleration value is greater than +9.81, which correspond to the
180 * acceleration of the device (+A m/s^2) minus the force of
181 * gravity (-9.81 m/s^2).
182 *
183 *
184 * Magnetic Field
185 * --------------
186 *
187 * All values are in micro-Tesla (uT) and measure the ambient magnetic
188 * field in the X, Y and Z axis.
Mike Lockwooda2414312009-11-03 10:29:50 -0500189 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700190 * Magnetic Field sensors return sensor events for all 3 axes at a constant
191 * rate defined by setDelay().
192 *
Kevin Powell4ec14c12010-07-19 19:12:15 -0700193 * Gyroscope
194 * ---------
195 * All values are in radians/second and measure the rate of rotation
196 * around the X, Y and Z axis. The coordinate system is the same as is
Mathias Agopianc04e5f62010-09-14 10:53:55 -0700197 * used for the acceleration sensor. Rotation is positive in the
198 * counter-clockwise direction (right-hand rule). That is, an observer
199 * looking from some positive location on the x, y or z axis at a device
200 * positioned on the origin would report positive rotation if the device
201 * appeared to be rotating counter clockwise. Note that this is the
202 * standard mathematical definition of positive rotation and does not agree
203 * with the definition of roll given earlier.
204 * The range should at least be 17.45 rad/s (ie: ~1000 deg/s).
Kevin Powell4ec14c12010-07-19 19:12:15 -0700205 *
Mike Lockwooda2414312009-11-03 10:29:50 -0500206 * Proximity
207 * ---------
208 *
209 * The distance value is measured in centimeters. Note that some proximity
210 * sensors only support a binary "close" or "far" measurement. In this case,
211 * the sensor should report its maxRange value in the "far" state and a value
212 * less than maxRange in the "near" state.
213 *
Mathias Agopian478994a2010-07-23 17:23:43 -0700214 * Proximity sensors report a value only when it changes and each time the
215 * sensor is enabled. setDelay() is ignored.
Mathias Agopian66a40952010-07-22 17:11:50 -0700216 *
Mike Lockwooda2414312009-11-03 10:29:50 -0500217 * Light
218 * -----
219 *
220 * The light sensor value is returned in SI lux units.
221 *
Mathias Agopian478994a2010-07-23 17:23:43 -0700222 * Light sensors report a value only when it changes and each time the
223 * sensor is enabled. setDelay() is ignored.
Mathias Agopian66a40952010-07-22 17:11:50 -0700224 *
Mathias Agopian1832f552010-07-29 15:22:30 -0700225 * Pressure
226 * --------
227 *
228 * The pressure sensor value is returned in hectopascal (hPa)
229 *
230 * Pressure sensors report events at a constant rate defined by setDelay().
231 *
Kevin Powell4ec14c12010-07-19 19:12:15 -0700232 * Gravity
233 * -------
234 * A gravity output indicates the direction of and magnitude of gravity in the devices's
235 * coordinates. On Earth, the magnitude is 9.8. Units are m/s^2. The coordinate system
236 * is the same as is used for the acceleration sensor.
Mathias Agopian42b743c2010-11-22 15:55:32 -0800237 * When the device is at rest, the output of the gravity sensor should be identical
238 * to that of the accelerometer.
Kevin Powell4ec14c12010-07-19 19:12:15 -0700239 *
240 * Linear Acceleration
241 * -------------------
242 * Indicates the linear acceleration of the device in device coordinates, not including gravity.
243 * This output is essentially Acceleration - Gravity. Units are m/s^2. The coordinate system is
244 * the same as is used for the acceleration sensor.
Mathias Agopian42b743c2010-11-22 15:55:32 -0800245 * The output of the accelerometer, gravity and linear-acceleration sensors must obey the
246 * following relation:
247 *
248 * acceleration = gravity + linear-acceleration
249 *
Kevin Powell4ec14c12010-07-19 19:12:15 -0700250 *
251 * Rotation Vector
252 * ---------------
253 * A rotation vector represents the orientation of the device as a combination
254 * of an angle and an axis, in which the device has rotated through an angle
255 * theta around an axis <x, y, z>. The three elements of the rotation vector
256 * are <x*sin(theta/2), y*sin(theta/2), z*sin(theta/2)>, such that the magnitude
257 * of the rotation vector is equal to sin(theta/2), and the direction of the
258 * rotation vector is equal to the direction of the axis of rotation. The three
259 * elements of the rotation vector are equal to the last three components of a
260 * unit quaternion <cos(theta/2), x*sin(theta/2), y*sin(theta/2), z*sin(theta/2)>.
261 * Elements of the rotation vector are unitless. The x, y, and z axis are defined
262 * in the same was as for the acceleration sensor.
Mathias Agopian42b743c2010-11-22 15:55:32 -0800263 *
264 * The rotation-vector is stored as:
265 *
266 * sensors_event_t.data[0] = x*sin(theta/2)
267 * sensors_event_t.data[1] = y*sin(theta/2)
268 * sensors_event_t.data[2] = z*sin(theta/2)
269 * sensors_event_t.data[3] = cos(theta/2)
270 *
Urs Fleischd2ed15a2010-12-29 17:00:33 +0100271 * Relative Humidity
272 * -----------------
273 *
274 * A relative humidity sensor measures relative ambient air humidity and
275 * returns a value in percent.
276 *
277 * Relative humidity sensors report a value only when it changes and each
278 * time the sensor is enabled. setDelay() is ignored.
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800279 */
Kevin Powell4ec14c12010-07-19 19:12:15 -0700280
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800281typedef struct {
282 union {
283 float v[3];
284 struct {
285 float x;
286 float y;
287 float z;
288 };
289 struct {
290 float azimuth;
291 float pitch;
292 float roll;
293 };
294 };
295 int8_t status;
296 uint8_t reserved[3];
297} sensors_vec_t;
298
299/**
300 * Union of the various types of sensor data
301 * that can be returned.
302 */
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700303typedef struct sensors_event_t {
304 /* must be sizeof(struct sensors_event_t) */
305 int32_t version;
306
307 /* sensor identifier */
308 int32_t sensor;
309
310 /* sensor type */
311 int32_t type;
312
313 /* reserved */
314 int32_t reserved0;
315
316 /* time is in nanosecond */
317 int64_t timestamp;
318
319 union {
320 float data[16];
321
322 /* acceleration values are in meter per second per second (m/s^2) */
323 sensors_vec_t acceleration;
324
325 /* magnetic vector values are in micro-Tesla (uT) */
326 sensors_vec_t magnetic;
327
328 /* orientation values are in degrees */
329 sensors_vec_t orientation;
330
Mathias Agopianc04e5f62010-09-14 10:53:55 -0700331 /* gyroscope values are in rad/s */
332 sensors_vec_t gyro;
333
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700334 /* temperature is in degrees centigrade (Celsius) */
335 float temperature;
336
337 /* distance in centimeters */
338 float distance;
339
340 /* light in SI lux units */
341 float light;
Mathias Agopian1832f552010-07-29 15:22:30 -0700342
343 /* pressure in hectopascal (hPa) */
344 float pressure;
Urs Fleischd2ed15a2010-12-29 17:00:33 +0100345
346 /* relative humidity in percent */
347 float relative_humidity;
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700348 };
349 uint32_t reserved1[4];
350} sensors_event_t;
351
352
353
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800354struct sensor_t;
355
356/**
357 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
358 * and the fields of this data structure must begin with hw_module_t
359 * followed by module specific information.
360 */
361struct sensors_module_t {
362 struct hw_module_t common;
363
364 /**
365 * Enumerate all available sensors. The list is returned in "list".
366 * @return number of sensors in the list
367 */
368 int (*get_sensors_list)(struct sensors_module_t* module,
369 struct sensor_t const** list);
370};
371
372struct sensor_t {
373 /* name of this sensors */
374 const char* name;
375 /* vendor of the hardware part */
376 const char* vendor;
377 /* version of the hardware part + driver. The value of this field is
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700378 * left to the implementation and doesn't have to be monotonically
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800379 * increasing.
380 */
381 int version;
382 /* handle that identifies this sensors. This handle is used to activate
383 * and deactivate this sensor. The value of the handle must be 8 bits
384 * in this version of the API.
385 */
386 int handle;
387 /* this sensor's type. */
388 int type;
389 /* maximaum range of this sensor's value in SI units */
390 float maxRange;
391 /* smallest difference between two values reported by this sensor */
392 float resolution;
393 /* rough estimate of this sensor's power consumption in mA */
394 float power;
Mathias Agopian1511e202010-07-29 15:33:22 -0700395 /* minimum delay allowed between events in microseconds. A value of zero
396 * means that this sensor doesn't report events at a constant rate, but
397 * rather only when a new data is available */
398 int32_t minDelay;
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800399 /* reserved fields, must be zero */
Mathias Agopian1511e202010-07-29 15:33:22 -0700400 void* reserved[8];
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800401};
402
403
404/**
405 * Every device data structure must begin with hw_device_t
406 * followed by module specific public methods and attributes.
407 */
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700408struct sensors_poll_device_t {
409 struct hw_device_t common;
410
411 /** Activate/deactivate one sensor.
412 *
413 * @param handle is the handle of the sensor to change.
414 * @param enabled set to 1 to enable, or 0 to disable the sensor.
415 *
416 * @return 0 on success, negative errno code otherwise
417 */
418 int (*activate)(struct sensors_poll_device_t *dev,
419 int handle, int enabled);
420
421 /**
Mathias Agopian1511e202010-07-29 15:33:22 -0700422 * Set the delay between sensor events in nanoseconds for a given sensor.
423 * It is an error to set a delay inferior to the value defined by
424 * sensor_t::minDelay. If sensor_t::minDelay is zero, setDelay() is
425 * ignored and returns 0.
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700426 *
427 * @return 0 if successful, < 0 on error
428 */
429 int (*setDelay)(struct sensors_poll_device_t *dev,
430 int handle, int64_t ns);
431
432 /**
433 * Returns an array of sensor data.
Mathias Agopian1511e202010-07-29 15:33:22 -0700434 * This function must block until events are available.
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700435 *
436 * @return the number of events read on success, or -errno in case of an error.
Mathias Agopian1511e202010-07-29 15:33:22 -0700437 * This function should never return 0 (no event).
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700438 *
439 */
440 int (*poll)(struct sensors_poll_device_t *dev,
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700441 sensors_event_t* data, int count);
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700442};
443
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800444/** convenience API for opening and closing a device */
445
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700446static inline int sensors_open(const struct hw_module_t* module,
447 struct sensors_poll_device_t** device) {
448 return module->methods->open(module,
449 SENSORS_HARDWARE_POLL, (struct hw_device_t**)device);
450}
451
452static inline int sensors_close(struct sensors_poll_device_t* device) {
453 return device->common.close(&device->common);
454}
455
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800456__END_DECLS
457
Mathias Agopian98c53092010-07-19 15:32:24 -0700458#include <hardware/sensors_deprecated.h>
459
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800460#endif // ANDROID_SENSORS_INTERFACE_H