battery.h

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/**
 * @file battery.h
 *
 * Library calls for battery functionality.
 *
 * @author Julian Oes <julian@oes.ch>
 */

#pragma once

#include <uORB/topics/battery_status.h>
#include <drivers/drv_hrt.h>
#include <px4_platform_common/module_params.h>


class Battery : public ModuleParams
{
public:
    Battery();

    /**
     * Reset all battery stats and report invalid/nothing.
     */
    void reset(battery_status_s *battery_status);

    /**
     * Get the battery cell count
     */
    int cell_count() { return _param_bat_n_cells.get(); }

    /**
     * Get the empty voltage per cell
     */
    float empty_cell_voltage() { return _param_bat_v_empty.get(); }

    /**
     * Get the full voltage per cell
     */
    float full_cell_voltage() { return _param_bat_v_charged.get(); }

    /**
     * Update current battery status message.
     *
     * @param voltage_v: current voltage in V
     * @param current_a: current current in A
     * @param connected: Battery is connected
     * @param selected_source: This battery is on the brick that the selected source for selected_source
     * @param priority: The brick number -1. The term priority refers to the Vn connection on the LTC4417
     * @param throttle_normalized: throttle from 0 to 1
     */
    void updateBatteryStatus(hrt_abstime timestamp, float voltage_v, float current_a,
                 bool connected, bool selected_source, int priority,
                 float throttle_normalized,
                 bool armed, battery_status_s *status);

private:
    void filterVoltage(float voltage_v);
    void filterThrottle(float throttle);
    void filterCurrent(float current_a);
    void sumDischarged(hrt_abstime timestamp, float current_a);
    void estimateRemaining(float voltage_v, float current_a, float throttle, bool armed);
    void determineWarning(bool connected);
    void computeScale();

    DEFINE_PARAMETERS(
        (ParamFloat<px4::params::BAT_V_EMPTY>) _param_bat_v_empty,
        (ParamFloat<px4::params::BAT_V_CHARGED>) _param_bat_v_charged,
        (ParamInt<px4::params::BAT_N_CELLS>) _param_bat_n_cells,
        (ParamFloat<px4::params::BAT_CAPACITY>) _param_bat_capacity,
        (ParamFloat<px4::params::BAT_V_LOAD_DROP>) _param_bat_v_load_drop,
        (ParamFloat<px4::params::BAT_R_INTERNAL>) _param_bat_r_internal,
        (ParamFloat<px4::params::BAT_LOW_THR>) _param_bat_low_thr,
        (ParamFloat<px4::params::BAT_CRIT_THR>) _param_bat_crit_thr,
        (ParamFloat<px4::params::BAT_EMERGEN_THR>) _param_bat_emergen_thr
    )

    bool _battery_initialized = false;
    float _voltage_filtered_v = -1.f;
    float _throttle_filtered = -1.f;
    float _current_filtered_a = -1.f;
    float _discharged_mah = 0.f;
    float _discharged_mah_loop = 0.f;
    float _remaining_voltage = -1.f;        ///< normalized battery charge level remaining based on voltage
    float _remaining = -1.f;            ///< normalized battery charge level, selected based on config param
    float _scale = 1.f;
    uint8_t _warning;
    hrt_abstime _last_timestamp;
};