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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* This module provides the component definitions used to represent sensor
* data employed by the online sensor calibration algorithms.
*/
#ifndef LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
#define LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
#include <sys/types.h>
#include <cstdint>
#include <cstring>
#include "common/math/macros.h"
namespace online_calibration {
// Defines an invalid or uninitialized temperature value (referenced from
// common/math/macros.h).
constexpr float kInvalidTemperatureCelsius = INVALID_TEMPERATURE_CELSIUS;
// Unit conversion from nanoseconds to microseconds.
constexpr uint64_t NanoToMicroseconds(uint64_t x) { return x / 1000; }
// Identifies the various sensing devices used by the calibration algorithms.
enum class SensorType : int8_t {
kUndefined = 0,
kAccelerometerMps2 = 1, // 3-axis sensor (units = meter/sec^2).
kGyroscopeRps = 2, // 3-axis sensor (units = radian/sec).
kMagnetometerUt = 3, // 3-axis sensor (units = micro-Tesla).
kTemperatureCelsius = 4, // 1-axis sensor (units = degrees Celsius).
kBarometerHpa = 5, // 1-axis sensor (units = hecto-Pascal).
kWifiM = 6, // 3-axis sensor (units = meter).
kProximity = 7, // 1-axis sensor (units = ?).
kHallEffect = 8, // 1-axis sensor (units = ?).
kHingeAngle = 9, // 1-axis sensor (units = degrees).
};
// Helper function for determining if a sensor type is 3-axis, otherwise it's
// single-axis.
inline bool is_three_axis(SensorType type) {
return type == SensorType::kAccelerometerMps2 ||
type == SensorType::kGyroscopeRps ||
type == SensorType::kMagnetometerUt;
}
/*
* SensorData is a generalized data structure used to represent sensor samples
* produced by either a single- or three-axis device. Usage is implied through
* the sensor type (i.e., Gyroscope is a three-axis sensor and would therefore
* use all elements of 'data'; a pressure sensor is single-dimensional and would
* use 'data[SensorIndex::kSingleAxis]'). This arbitration is determined
* at the algorithm wrapper level where knowledge of a sensor's dimensionality
* is clearly understood.
*
* NOTE: The unified dimensional representation makes it convenient to pass
* either type of data into the interface functions defined in the
* OnlineCalibration. Additionally, this approach, although admittedly wasteful
* for single-axis sensors, allows one to avoid dynamic memory allocation for
* hardware systems where having a fixed memory footprint is either required or
* extremely desireable.
*/
// Axis index definitions for SensorData::data.
enum SensorIndex : int8_t {
kSingleAxis = 0,
kXAxis = kSingleAxis,
kYAxis = 1,
kZAxis = 2,
};
struct SensorData {
// Sensor sample timestamp.
uint64_t timestamp_nanos;
// Generalized sensor sample (represents either single- or three-axis data).
float data[3];
// Indicates the type of sensor this data originated from.
SensorType type;
SensorData() : timestamp_nanos(0), type(SensorType::kUndefined) {
memset(data, 0, sizeof(data));
}
SensorData(SensorType type, uint64_t timestamp_nanos, float x_axis,
float y_axis, float z_axis)
: timestamp_nanos(timestamp_nanos), type(type) {
data[SensorIndex::kXAxis] = x_axis;
data[SensorIndex::kYAxis] = y_axis;
data[SensorIndex::kZAxis] = z_axis;
}
SensorData(SensorType type, uint64_t timestamp_nanos,
float single_axis_sample)
: timestamp_nanos(timestamp_nanos), type(type) {
data[SensorIndex::kSingleAxis] = single_axis_sample;
}
};
} // namespace online_calibration
#endif // LOCATION_LBS_CONTEXTHUB_NANOAPPS_CALIBRATION_ONLINE_CALIBRATION_COMMON_DATA_SENSOR_DATA_H_
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