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 48 extern "C" { 49 #endif 50 51 52 /* 53 * Sensor types 54 * (keep in sync with hardware/sensor.h) 55 */ 56 57 enum { 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 */ 68 enum { 69 ASENSOR_STATUS_UNRELIABLE = 0, 70 ASENSOR_STATUS_ACCURACY_LOW = 1, 71 ASENSOR_STATUS_ACCURACY_MEDIUM = 2, 72 ASENSOR_STATUS_ACCURACY_HIGH = 3 73 }; 74 75 /* 76 * A few useful constants 77 */ 78 79 /* Earth's gravity in m/s^2 */ 80 #define ASENSOR_STANDARD_GRAVITY (9.80665f) 81 /* Maximum magnetic field on Earth's surface in uT */ 82 #define ASENSOR_MAGNETIC_FIELD_EARTH_MAX (60.0f) 83 /* Minimum magnetic field on Earth's surface in uT*/ 84 #define ASENSOR_MAGNETIC_FIELD_EARTH_MIN (30.0f) 85 86 /* 87 * A sensor event. 88 */ 89 90 /* NOTE: Must match hardware/sensors.h */ 91 typedef struct ASensorVector { 92 union { 93 float v[3]; 94 struct { 95 float x; 96 float y; 97 float z; 98 }; 99 struct { 100 float azimuth; 101 float pitch; 102 float roll; 103 }; 104 }; 105 int8_t status; 106 uint8_t reserved[3]; 107 } ASensorVector; 108 109 /* NOTE: Must match hardware/sensors.h */ 110 typedef struct ASensorEvent { 111 int32_t version; /* sizeof(struct ASensorEvent) */ 112 int32_t sensor; 113 int32_t type; 114 int32_t reserved0; 115 int64_t timestamp; 116 union { 117 float data[16]; 118 ASensorVector vector; 119 ASensorVector acceleration; 120 ASensorVector magnetic; 121 float temperature; 122 float distance; 123 float light; 124 float pressure; 125 }; 126 int32_t reserved1[4]; 127 } ASensorEvent; 128 129 130 struct ASensorManager; 131 typedef struct ASensorManager ASensorManager; 132 133 struct ASensorEventQueue; 134 typedef struct ASensorEventQueue ASensorEventQueue; 135 136 struct ASensor; 137 typedef struct ASensor ASensor; 138 typedef ASensor const* ASensorRef; 139 typedef ASensorRef const* ASensorList; 140 141 /*****************************************************************************/ 142 143 /* 144 * Get a reference to the sensor manager. ASensorManager is a singleton. 145 * 146 * Example: 147 * 148 * ASensorManager* sensorManager = ASensorManager_getInstance(); 149 * 150 */ 151 ASensorManager* ASensorManager_getInstance(); 152 153 154 /* 155 * Returns the list of available sensors. 156 */ 157 int ASensorManager_getSensorList(ASensorManager* manager, ASensorList* list); 158 159 /* 160 * Returns the default sensor for the given type, or NULL if no sensor 161 * of that type exist. 162 */ 163 ASensor const* ASensorManager_getDefaultSensor(ASensorManager* manager, int type); 164 165 /* 166 * Creates a new sensor event queue and associate it with a looper. 167 */ 168 ASensorEventQueue* ASensorManager_createEventQueue(ASensorManager* manager, 169 ALooper* looper, int ident, ALooper_callbackFunc callback, void* data); 170 171 /* 172 * Destroys the event queue and free all resources associated to it. 173 */ 174 int ASensorManager_destroyEventQueue(ASensorManager* manager, ASensorEventQueue* queue); 175 176 177 /*****************************************************************************/ 178 179 /* 180 * Enable the selected sensor. Returns a negative error code on failure. 181 */ 182 int ASensorEventQueue_enableSensor(ASensorEventQueue* queue, ASensor const* sensor); 183 184 /* 185 * Disable the selected sensor. Returns a negative error code on failure. 186 */ 187 int ASensorEventQueue_disableSensor(ASensorEventQueue* queue, ASensor const* sensor); 188 189 /* 190 * Sets the delivery rate of events in microseconds for the given sensor. 191 * Note that this is a hint only, generally event will arrive at a higher 192 * rate. It is an error to set a rate inferior to the value returned by 193 * ASensor_getMinDelay(). 194 * Returns a negative error code on failure. 195 */ 196 int ASensorEventQueue_setEventRate(ASensorEventQueue* queue, ASensor const* sensor, int32_t usec); 197 198 /* 199 * Returns true if there are one or more events available in the 200 * sensor queue. Returns 1 if the queue has events; 0 if 201 * it does not have events; and a negative value if there is an error. 202 */ 203 int ASensorEventQueue_hasEvents(ASensorEventQueue* queue); 204 205 /* 206 * Returns the next available events from the queue. Returns a negative 207 * value if no events are available or an error has occurred, otherwise 208 * the number of events returned. 209 * 210 * Examples: 211 * ASensorEvent event; 212 * ssize_t numEvent = ASensorEventQueue_getEvents(queue, &event, 1); 213 * 214 * ASensorEvent eventBuffer[8]; 215 * ssize_t numEvent = ASensorEventQueue_getEvents(queue, eventBuffer, 8); 216 * 217 */ 218 ssize_t ASensorEventQueue_getEvents(ASensorEventQueue* queue, 219 ASensorEvent* events, size_t count); 220 221 222 /*****************************************************************************/ 223 224 /* 225 * Returns this sensor's name (non localized) 226 */ 227 const char* ASensor_getName(ASensor const* sensor); 228 229 /* 230 * Returns this sensor's vendor's name (non localized) 231 */ 232 const char* ASensor_getVendor(ASensor const* sensor); 233 234 /* 235 * Return this sensor's type 236 */ 237 int ASensor_getType(ASensor const* sensor); 238 239 /* 240 * Returns this sensors's resolution 241 */ 242 float ASensor_getResolution(ASensor const* sensor) __NDK_FPABI__; 243 244 /* 245 * Returns the minimum delay allowed between events in microseconds. 246 * A value of zero means that this sensor doesn't report events at a 247 * constant rate, but rather only when a new data is available. 248 */ 249 int ASensor_getMinDelay(ASensor const* sensor); 250 251 252 #ifdef __cplusplus 253 }; 254 #endif 255 256 #endif // ANDROID_SENSOR_H 257