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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
61
62/**
63 * Values returned by the accelerometer in various locations in the universe.
64 * all values are in SI units (m/s^2)
65 */
66
67#define GRAVITY_SUN (275.0f)
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080068#define GRAVITY_EARTH (9.80665f)
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -080069
70/** Maximum magnetic field on Earth's surface */
71#define MAGNETIC_FIELD_EARTH_MAX (60.0f)
72
73/** Minimum magnetic field on Earth's surface */
74#define MAGNETIC_FIELD_EARTH_MIN (30.0f)
75
76
77/**
78 * status of each sensor
79 */
80
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
85
86/**
87 * Definition of the axis
88 * ----------------------
89 *
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.
95 *
96 * x<0 x>0
97 * ^
98 * |
99 * +-----------+--> y>0
100 * | |
101 * | |
102 * | |
103 * | | / z<0
104 * | | /
105 * | | /
106 * O-----------+/
107 * |[] [ ] []/
108 * +----------/+ y<0
109 * /
110 * /
111 * |/ z>0 (toward the sky)
112 *
113 * O: Origin (x=0,y=0,z=0)
114 *
115 *
116 * Orientation
117 * -----------
118 *
119 * All values are angles in degrees.
120 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700121 * Orientation sensors return sensor events for all 3 axes at a constant
122 * rate defined by setDelay().
123 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800124 * 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
127 *
128 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when
129 * the z-axis moves toward the y-axis.
130 *
131 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when
Mathias Agopian19ea59f2010-02-26 13:15:18 -0800132 * the x-axis moves towards the z-axis.
133 *
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):
137 *
138 * Z
139 * ^
140 * (+roll) .--> |
141 * / |
142 * | | roll: rotation around Y axis
143 * X <-------(.)
144 * Y
145 * note that +Y == -roll
146 *
147 *
148 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800149 * 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).
151 *
152 *
153 * Acceleration
154 * ------------
155 *
156 * All values are in SI units (m/s^2) and measure the acceleration of the
157 * device minus the force of gravity.
158 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700159 * Acceleration sensors return sensor events for all 3 axes at a constant
160 * rate defined by setDelay().
161 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800162 * 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
165 *
166 * Examples:
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.
169 *
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).
173 *
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).
178 *
179 *
180 * Magnetic Field
181 * --------------
182 *
183 * All values are in micro-Tesla (uT) and measure the ambient magnetic
184 * field in the X, Y and Z axis.
Mike Lockwooda2414312009-11-03 10:29:50 -0500185 *
Mathias Agopian66a40952010-07-22 17:11:50 -0700186 * Magnetic Field sensors return sensor events for all 3 axes at a constant
187 * rate defined by setDelay().
188 *
Mike Lockwooda2414312009-11-03 10:29:50 -0500189 * Proximity
190 * ---------
191 *
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.
196 *
Mathias Agopian478994a2010-07-23 17:23:43 -0700197 * Proximity sensors report a value only when it changes and each time the
198 * sensor is enabled. setDelay() is ignored.
Mathias Agopian66a40952010-07-22 17:11:50 -0700199 *
Mike Lockwooda2414312009-11-03 10:29:50 -0500200 * Light
201 * -----
202 *
203 * The light sensor value is returned in SI lux units.
204 *
Mathias Agopian478994a2010-07-23 17:23:43 -0700205 * Light sensors report a value only when it changes and each time the
206 * sensor is enabled. setDelay() is ignored.
Mathias Agopian66a40952010-07-22 17:11:50 -0700207 *
Mathias Agopian1832f552010-07-29 15:22:30 -0700208 * Pressure
209 * --------
210 *
211 * The pressure sensor value is returned in hectopascal (hPa)
212 *
213 * Pressure sensors report events at a constant rate defined by setDelay().
214 *
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800215 */
216typedef struct {
217 union {
218 float v[3];
219 struct {
220 float x;
221 float y;
222 float z;
223 };
224 struct {
225 float azimuth;
226 float pitch;
227 float roll;
228 };
229 };
230 int8_t status;
231 uint8_t reserved[3];
232} sensors_vec_t;
233
234/**
235 * Union of the various types of sensor data
236 * that can be returned.
237 */
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700238typedef struct sensors_event_t {
239 /* must be sizeof(struct sensors_event_t) */
240 int32_t version;
241
242 /* sensor identifier */
243 int32_t sensor;
244
245 /* sensor type */
246 int32_t type;
247
248 /* reserved */
249 int32_t reserved0;
250
251 /* time is in nanosecond */
252 int64_t timestamp;
253
254 union {
255 float data[16];
256
257 /* acceleration values are in meter per second per second (m/s^2) */
258 sensors_vec_t acceleration;
259
260 /* magnetic vector values are in micro-Tesla (uT) */
261 sensors_vec_t magnetic;
262
263 /* orientation values are in degrees */
264 sensors_vec_t orientation;
265
266 /* temperature is in degrees centigrade (Celsius) */
267 float temperature;
268
269 /* distance in centimeters */
270 float distance;
271
272 /* light in SI lux units */
273 float light;
Mathias Agopian1832f552010-07-29 15:22:30 -0700274
275 /* pressure in hectopascal (hPa) */
276 float pressure;
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700277 };
278 uint32_t reserved1[4];
279} sensors_event_t;
280
281
282
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800283struct sensor_t;
284
285/**
286 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
287 * and the fields of this data structure must begin with hw_module_t
288 * followed by module specific information.
289 */
290struct sensors_module_t {
291 struct hw_module_t common;
292
293 /**
294 * Enumerate all available sensors. The list is returned in "list".
295 * @return number of sensors in the list
296 */
297 int (*get_sensors_list)(struct sensors_module_t* module,
298 struct sensor_t const** list);
299};
300
301struct sensor_t {
302 /* name of this sensors */
303 const char* name;
304 /* vendor of the hardware part */
305 const char* vendor;
306 /* version of the hardware part + driver. The value of this field is
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700307 * left to the implementation and doesn't have to be monotonically
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800308 * increasing.
309 */
310 int version;
311 /* handle that identifies this sensors. This handle is used to activate
312 * and deactivate this sensor. The value of the handle must be 8 bits
313 * in this version of the API.
314 */
315 int handle;
316 /* this sensor's type. */
317 int type;
318 /* maximaum range of this sensor's value in SI units */
319 float maxRange;
320 /* smallest difference between two values reported by this sensor */
321 float resolution;
322 /* rough estimate of this sensor's power consumption in mA */
323 float power;
Mathias Agopian1511e202010-07-29 15:33:22 -0700324 /* minimum delay allowed between events in microseconds. A value of zero
325 * means that this sensor doesn't report events at a constant rate, but
326 * rather only when a new data is available */
327 int32_t minDelay;
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800328 /* reserved fields, must be zero */
Mathias Agopian1511e202010-07-29 15:33:22 -0700329 void* reserved[8];
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800330};
331
332
333/**
334 * Every device data structure must begin with hw_device_t
335 * followed by module specific public methods and attributes.
336 */
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700337struct sensors_poll_device_t {
338 struct hw_device_t common;
339
340 /** Activate/deactivate one sensor.
341 *
342 * @param handle is the handle of the sensor to change.
343 * @param enabled set to 1 to enable, or 0 to disable the sensor.
344 *
345 * @return 0 on success, negative errno code otherwise
346 */
347 int (*activate)(struct sensors_poll_device_t *dev,
348 int handle, int enabled);
349
350 /**
Mathias Agopian1511e202010-07-29 15:33:22 -0700351 * Set the delay between sensor events in nanoseconds for a given sensor.
352 * It is an error to set a delay inferior to the value defined by
353 * sensor_t::minDelay. If sensor_t::minDelay is zero, setDelay() is
354 * ignored and returns 0.
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700355 *
356 * @return 0 if successful, < 0 on error
357 */
358 int (*setDelay)(struct sensors_poll_device_t *dev,
359 int handle, int64_t ns);
360
361 /**
362 * Returns an array of sensor data.
Mathias Agopian1511e202010-07-29 15:33:22 -0700363 * This function must block until events are available.
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700364 *
365 * @return the number of events read on success, or -errno in case of an error.
Mathias Agopian1511e202010-07-29 15:33:22 -0700366 * This function should never return 0 (no event).
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700367 *
368 */
369 int (*poll)(struct sensors_poll_device_t *dev,
Mathias Agopiancdefccd2010-07-15 18:29:03 -0700370 sensors_event_t* data, int count);
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700371};
372
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800373/** convenience API for opening and closing a device */
374
Mathias Agopianb1e212e2010-07-08 16:44:54 -0700375static inline int sensors_open(const struct hw_module_t* module,
376 struct sensors_poll_device_t** device) {
377 return module->methods->open(module,
378 SENSORS_HARDWARE_POLL, (struct hw_device_t**)device);
379}
380
381static inline int sensors_close(struct sensors_poll_device_t* device) {
382 return device->common.close(&device->common);
383}
384
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800385__END_DECLS
386
Mathias Agopian98c53092010-07-19 15:32:24 -0700387#include <hardware/sensors_deprecated.h>
388
The Android Open Source Projectf53ebec2009-03-03 19:32:14 -0800389#endif // ANDROID_SENSORS_INTERFACE_H