sensor.h revision b412f6e203b38f8047f760261a5e3dc6d0722f08 
1/*
2 * Copyright (C) 2010 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
18#ifndef ANDROID_SENSOR_H
19#define ANDROID_SENSOR_H
20
21/******************************************************************
22 *
23 * IMPORTANT NOTICE:
24 *
25 *   This file is part of Android's set of stable system headers
26 *   exposed by the Android NDK (Native Development Kit).
27 *
28 *   Third-party source AND binary code relies on the definitions
29 *   here to be FROZEN ON ALL UPCOMING PLATFORM RELEASES.
30 *
31 *   - DO NOT MODIFY ENUMS (EXCEPT IF YOU ADD NEW 32-BIT VALUES)
32 *   - DO NOT MODIFY CONSTANTS OR FUNCTIONAL MACROS
33 *   - DO NOT CHANGE THE SIGNATURE OF FUNCTIONS IN ANY WAY
34 *   - DO NOT CHANGE THE LAYOUT OR SIZE OF STRUCTURES
35 */
36
37/*
38 * Structures and functions to receive and process sensor events in
39 * native code.
40 *
41 */
42
43#include <sys/types.h>
44
45#include <android/looper.h>
46
47#ifdef __cplusplus
48extern "C" {
49#endif
50
51
52/*
53 * Sensor types
54 * (keep in sync with hardware/sensor.h)
55 */
56
57enum {
58    ASENSOR_TYPE_ACCELEROMETER      = 1,
59    ASENSOR_TYPE_MAGNETIC_FIELD     = 2,
60    ASENSOR_TYPE_GYROSCOPE          = 4,
61    ASENSOR_TYPE_LIGHT              = 5,
62    ASENSOR_TYPE_PROXIMITY          = 8
63};
64
65/*
66 * Sensor accuracy measure
67 */
68enum {
69    ASENSOR_STATUS_NO_CONTACT       = -1,
70    ASENSOR_STATUS_UNRELIABLE       = 0,
71    ASENSOR_STATUS_ACCURACY_LOW     = 1,
72    ASENSOR_STATUS_ACCURACY_MEDIUM  = 2,
73    ASENSOR_STATUS_ACCURACY_HIGH    = 3
74};
75
76/*
77 * Sensor Reporting Modes.
78 */
79enum {
80    AREPORTING_MODE_CONTINUOUS = 0,
81    AREPORTING_MODE_ON_CHANGE = 1,
82    AREPORTING_MODE_ONE_SHOT = 2,
83    AREPORTING_MODE_SPECIAL_TRIGGER = 3
84};
85
86/*
87 * A few useful constants
88 */
89
90/* Earth's gravity in m/s^2 */
91#define ASENSOR_STANDARD_GRAVITY            (9.80665f)
92/* Maximum magnetic field on Earth's surface in uT */
93#define ASENSOR_MAGNETIC_FIELD_EARTH_MAX    (60.0f)
94/* Minimum magnetic field on Earth's surface in uT*/
95#define ASENSOR_MAGNETIC_FIELD_EARTH_MIN    (30.0f)
96
97/*
98 * A sensor event.
99 */
100
101/* NOTE: Must match hardware/sensors.h */
102typedef struct ASensorVector {
103    union {
104        float v[3];
105        struct {
106            float x;
107            float y;
108            float z;
109        };
110        struct {
111            float azimuth;
112            float pitch;
113            float roll;
114        };
115    };
116    int8_t status;
117    uint8_t reserved[3];
118} ASensorVector;
119
120typedef struct AMetaDataEvent {
121    int32_t what;
122    int32_t sensor;
123} AMetaDataEvent;
124
125typedef struct AUncalibratedEvent {
126  union {
127    float uncalib[3];
128    struct {
129      float x_uncalib;
130      float y_uncalib;
131      float z_uncalib;
132    };
133  };
134  union {
135    float bias[3];
136    struct {
137      float x_bias;
138      float y_bias;
139      float z_bias;
140    };
141  };
142} AUncalibratedEvent;
143
144typedef struct AHeartRateEvent {
145  float bpm;
146  int8_t status;
147} AHeartRateEvent;
148
149/* NOTE: Must match hardware/sensors.h */
150typedef struct ASensorEvent {
151    int32_t version; /* sizeof(struct ASensorEvent) */
152    int32_t sensor;
153    int32_t type;
154    int32_t reserved0;
155    int64_t timestamp;
156    union {
157        union {
158            float           data[16];
159            ASensorVector   vector;
160            ASensorVector   acceleration;
161            ASensorVector   magnetic;
162            float           temperature;
163            float           distance;
164            float           light;
165            float           pressure;
166            float           relative_humidity;
167            AUncalibratedEvent uncalibrated_gyro;
168            AUncalibratedEvent uncalibrated_magnetic;
169            AMetaDataEvent meta_data;
170            AHeartRateEvent heart_rate;
171        };
172        union {
173            uint64_t        data[8];
174            uint64_t        step_counter;
175        } u64;
176    };
177
178    uint32_t flags;
179    int32_t reserved1[3];
180} ASensorEvent;
181
182struct ASensorManager;
183typedef struct ASensorManager ASensorManager;
184
185struct ASensorEventQueue;
186typedef struct ASensorEventQueue ASensorEventQueue;
187
188struct ASensor;
189typedef struct ASensor ASensor;
190typedef ASensor const* ASensorRef;
191typedef ASensorRef const* ASensorList;
192
193/*****************************************************************************/
194
195/*
196 * Returns the list of available sensors.
197 */
198int ASensorManager_getSensorList(ASensorManager* manager, ASensorList* list);
199
200/*
201 * Returns the default sensor for the given type, or NULL if no sensor
202 * of that type exists.
203 */
204ASensor const* ASensorManager_getDefaultSensor(ASensorManager* manager, int type);
205
206/*
207 * Returns the default sensor with the given type and wakeUp properties or NULL if no sensor
208 * of this type and wakeUp properties exists.
209 */
210ASensor const* ASensorManager_getDefaultSensorEx(ASensorManager* manager, int type,
211        bool wakeUp);
212
213/*
214 * Creates a new sensor event queue and associate it with a looper.
215 */
216ASensorEventQueue* ASensorManager_createEventQueue(ASensorManager* manager,
217        ALooper* looper, int ident, ALooper_callbackFunc callback, void* data);
218
219/*
220 * Destroys the event queue and free all resources associated to it.
221 */
222int ASensorManager_destroyEventQueue(ASensorManager* manager, ASensorEventQueue* queue);
223
224
225/*****************************************************************************/
226
227/*
228 * Enable the selected sensor. Returns a negative error code on failure.
229 */
230int ASensorEventQueue_enableSensor(ASensorEventQueue* queue, ASensor const* sensor);
231
232/*
233 * Disable the selected sensor. Returns a negative error code on failure.
234 */
235int ASensorEventQueue_disableSensor(ASensorEventQueue* queue, ASensor const* sensor);
236
237/*
238 * Sets the delivery rate of events in microseconds for the given sensor.
239 * Note that this is a hint only, generally event will arrive at a higher
240 * rate. It is an error to set a rate inferior to the value returned by
241 * ASensor_getMinDelay().
242 * Returns a negative error code on failure.
243 */
244int ASensorEventQueue_setEventRate(ASensorEventQueue* queue, ASensor const* sensor, int32_t usec);
245
246/*
247 * Returns true if there are one or more events available in the
248 * sensor queue.  Returns 1 if the queue has events; 0 if
249 * it does not have events; and a negative value if there is an error.
250 */
251int ASensorEventQueue_hasEvents(ASensorEventQueue* queue);
252
253/*
254 * Returns the next available events from the queue.  Returns a negative
255 * value if no events are available or an error has occurred, otherwise
256 * the number of events returned.
257 *
258 * Examples:
259 *   ASensorEvent event;
260 *   ssize_t numEvent = ASensorEventQueue_getEvents(queue, &event, 1);
261 *
262 *   ASensorEvent eventBuffer[8];
263 *   ssize_t numEvent = ASensorEventQueue_getEvents(queue, eventBuffer, 8);
264 *
265 */
266ssize_t ASensorEventQueue_getEvents(ASensorEventQueue* queue,
267                ASensorEvent* events, size_t count);
268
269
270/*****************************************************************************/
271
272/*
273 * Returns this sensor's name (non localized)
274 */
275const char* ASensor_getName(ASensor const* sensor);
276
277/*
278 * Returns this sensor's vendor's name (non localized)
279 */
280const char* ASensor_getVendor(ASensor const* sensor);
281
282/*
283 * Return this sensor's type
284 */
285int ASensor_getType(ASensor const* sensor);
286
287/*
288 * Returns this sensors's resolution
289 */
290float ASensor_getResolution(ASensor const* sensor);
291
292/*
293 * Returns the minimum delay allowed between events in microseconds.
294 * A value of zero means that this sensor doesn't report events at a
295 * constant rate, but rather only when a new data is available.
296 */
297int ASensor_getMinDelay(ASensor const* sensor);
298
299/*
300 * Returns the maximum size of batches for this sensor. Batches will often be
301 * smaller, as the hardware fifo might be used for other sensors.
302 */
303int ASensor_getFifoMaxEventCount(ASensor const* sensor);
304
305/*
306 * Returns the hardware batch fifo size reserved to this sensor.
307 */
308int ASensor_getFifoReservedEventCount(ASensor const* sensor);
309
310/*
311 * Returns this sensor's string type.
312 */
313const char* ASensor_getStringType(ASensor const* sensor);
314
315/*
316 * Returns the reporting mode for this sensor. One of AREPORTING_MODE_* constants.
317 */
318int ASensor_getReportingMode(ASensor const* sensor);
319
320/*
321 * Returns true if this is a wake up sensor, false otherwise.
322 */
323bool ASensor_isWakeUpSensor(ASensor const* sensor);
324
325#ifdef __cplusplus
326};
327#endif
328
329#endif // ANDROID_SENSOR_H
330