1 /*
2 * Copyright (C) 2018 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 * This module provides the component definitions used to represent sensor
19 * data employed by the online sensor calibration algorithms.
20 */
21
22 #ifndef LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
23 #define LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
24
25 #include <sys/types.h>
26
27 #include <cstdint>
28 #include <cstring>
29
30 #include "common/math/macros.h"
31
32 namespace online_calibration {
33
34 // Defines an invalid or uninitialized temperature value (referenced from
35 // common/math/macros.h).
36 constexpr float kInvalidTemperatureCelsius = INVALID_TEMPERATURE_CELSIUS;
37
38 // Unit conversion from nanoseconds to microseconds.
NanoToMicroseconds(uint64_t x)39 constexpr uint64_t NanoToMicroseconds(uint64_t x) { return x / 1000; }
40
41 // Identifies the various sensing devices used by the calibration algorithms.
42 enum class SensorType : int8_t {
43 kUndefined = 0,
44 kAccelerometerMps2 = 1, // 3-axis sensor (units = meter/sec^2).
45 kGyroscopeRps = 2, // 3-axis sensor (units = radian/sec).
46 kMagnetometerUt = 3, // 3-axis sensor (units = micro-Tesla).
47 kTemperatureCelsius = 4, // 1-axis sensor (units = degrees Celsius).
48 kBarometerHpa = 5, // 1-axis sensor (units = hecto-Pascal).
49 kWifiM = 6, // 3-axis sensor (units = meter).
50 kProximity = 7, // 1-axis sensor (units = ?).
51 };
52
53 // Helper function for determining if a sensor type is 3-axis, otherwise it's
54 // single-axis.
is_three_axis(SensorType type)55 inline bool is_three_axis(SensorType type) {
56 return type == SensorType::kAccelerometerMps2 ||
57 type == SensorType::kGyroscopeRps ||
58 type == SensorType::kMagnetometerUt;
59 }
60
61 /*
62 * SensorData is a generalized data structure used to represent sensor samples
63 * produced by either a single- or three-axis device. Usage is implied through
64 * the sensor type (i.e., Gyroscope is a three-axis sensor and would therefore
65 * use all elements of 'data'; a pressure sensor is single-dimensional and would
66 * use 'data[SensorIndex::kSingleAxis]'). This arbitration is determined
67 * at the algorithm wrapper level where knowledge of a sensor's dimensionality
68 * is clearly understood.
69 *
70 * NOTE: The unified dimensional representation makes it convenient to pass
71 * either type of data into the interface functions defined in the
72 * OnlineCalibration. Additionally, this approach, although admittedly wasteful
73 * for single-axis sensors, allows one to avoid dynamic memory allocation for
74 * hardware systems where having a fixed memory footprint is either required or
75 * extremely desireable.
76 */
77
78 // Axis index definitions for SensorData::data.
79 enum SensorIndex : int8_t {
80 kSingleAxis = 0,
81 kXAxis = kSingleAxis,
82 kYAxis = 1,
83 kZAxis = 2,
84 };
85
86 struct SensorData {
87 // Sensor sample timestamp.
88 uint64_t timestamp_nanos;
89
90 // Generalized sensor sample (represents either single- or three-axis data).
91 float data[3];
92
93 // Indicates the type of sensor this data originated from.
94 SensorType type;
95
SensorDataSensorData96 SensorData() : timestamp_nanos(0), type(SensorType::kUndefined) {
97 memset(data, 0, sizeof(data));
98 }
99
SensorDataSensorData100 SensorData(SensorType type, uint64_t timestamp_nanos, float x_axis,
101 float y_axis, float z_axis)
102 : timestamp_nanos(timestamp_nanos), type(type) {
103 data[SensorIndex::kXAxis] = x_axis;
104 data[SensorIndex::kYAxis] = y_axis;
105 data[SensorIndex::kZAxis] = z_axis;
106 }
107
SensorDataSensorData108 SensorData(SensorType type, uint64_t timestamp_nanos,
109 float single_axis_sample)
110 : timestamp_nanos(timestamp_nanos), type(type) {
111 data[SensorIndex::kSingleAxis] = single_axis_sample;
112 }
113 };
114
115 } // namespace online_calibration
116
117 #endif // LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
118