sac2020_imu.h

/**
 *             [ANOTHER FINE PRODUCT FROM THE NONSENSE FACTORY]
 *
 * Flight software for the Longhorn Rocketry Association's Spaceport America
 * Cup 2020 rocket. Built for the LRA Generation 2 flight computer, which also
 * flies in LRA's NASA Student Launch 2020 rocket. The configurability of the
 * software--combined with modularity and all-in-one-package style of the
 * Generation 2 flight computer--means the software can be easily adapted to run
 * in any high-power rocket.
 *
 * @file      sac2020_imu.h
 * @purpose   Device wrapper for the flight computer's inertial measurement
 *            unit.
 * @author    Stefan deBruyn
 * @updated   2/22/2020
 */

#ifndef SAC2020_IMU_H
#define SAC2020_IMU_H

#include <Adafruit_BNO055.h>
#include <Adafruit_Sensor.h>
#include "photic.h"

#include "utility/imumaths.h"

class Sac2020Imu final : public photic::Imu
{
public:
    /**
     * Initializes the BNO055.
     *
     * @ret     True if successful, false otherwise.
     */
    bool init()
    {
        bool success = m_bno055.begin();

        if (success)
        {
            m_bno055.setExtCrystalUse(true);
        }

        return success;
    }

    /**
     * Updates orientation and acceleration data with the BNO055's Euler angle
     * and linear accleration readings. Magnetometer data is disregarded.
     *
     * @ret     Always returns true.
     */
    bool update()
    {
        // Read in sensor events from device.
        sensors_event_t orient, accel;
        m_bno055.getEvent(&orient, Adafruit_BNO055::VECTOR_EULER);
        m_bno055.getEvent(&accel, Adafruit_BNO055::VECTOR_LINEARACCEL);

        // Populate orientation data. Currently this maps x, y, z to roll,
        // pitch, yaw, but I have no idea if this is correct.
        m_data.gyro_x = orient.orientation.x;
        m_data.gyro_y = orient.orientation.y;
        m_data.gyro_z = orient.orientation.z;

        // Populate acceleration data.
        m_data.accel_x = accel.acceleration.x;
        m_data.accel_y = accel.acceleration.y;
        m_data.accel_z = accel.acceleration.z;

        // Populate quaternion orientation. This does not go into the data
        // struct because it uses a proprietary class. Access with
        // Sac2020Imu::quat().
        m_quat = m_bno055.getQuat();

        return true;
    }

    /**
     * Gets quaternion orientation.
     *
     * @ret     Quaternion orientation relative to startup orientation.
     */
    imu::Quaternion quat()
    {
        return m_quat;
    }

    /**
     * Gets the calibration level of IMU components.
     *
     * @param   k_sys   System.
     * @param   k_gyro  Gyroscope.
     * @param   k_accel Accelerometer.
     * @param   k_mag   Magnetometer.
     */
    void get_calib(uint8_t* k_sys, uint8_t* k_gyro, uint8_t* k_accel,
                   uint8_t* k_mag)
    {
        m_bno055.getCalibration(k_sys, k_gyro, k_accel, k_mag);
    }

    /**
     * Gets the current temperature read by the IMU.
     *
     * @ret     Temperature in C.
     */
    int8_t get_temp()
    {
        return m_bno055.getTemp();
    }

private:
    /**
     * BNO055 driver.
     */
    Adafruit_BNO055 m_bno055;
    /**
     * Last sensed quaternion orientation.
     */
    imu::Quaternion m_quat;
};

#endif