input_rc.cpp

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/**
 * @file input_rc.cpp
 * @author Beat Küng <beat-kueng@gmx.net>
 *
 */

#include "input_rc.h"

#include <math.h>
#include <errno.h>
#include <px4_platform_common/posix.h>
#include <px4_platform_common/defines.h>


namespace vmount
{


InputRC::InputRC(bool do_stabilization, int aux_channel_roll, int aux_channel_pitch, int aux_channel_yaw)
    : _do_stabilization(do_stabilization)
{
    _aux_channels[0] = aux_channel_roll;
    _aux_channels[1] = aux_channel_pitch;
    _aux_channels[2] = aux_channel_yaw;
}

InputRC::~InputRC()
{
    if (_manual_control_setpoint_sub >= 0) {
        orb_unsubscribe(_manual_control_setpoint_sub);
    }
}

int InputRC::initialize()
{
    _manual_control_setpoint_sub = orb_subscribe(ORB_ID(manual_control_setpoint));

    if (_manual_control_setpoint_sub < 0) {
        return -errno;
    }

    return 0;
}

int InputRC::update_impl(unsigned int timeout_ms, ControlData **control_data, bool already_active)
{
    // Default to no change signalled by NULL.
    *control_data = nullptr;

    px4_pollfd_struct_t polls[1];
    polls[0].fd =       _manual_control_setpoint_sub;
    polls[0].events =   POLLIN;

    int ret = px4_poll(polls, 1, timeout_ms);

    if (ret < 0) {
        return -errno;
    }

    if (ret == 0) {
        // Timeout, leave NULL
    } else {
        if (polls[0].revents & POLLIN) {
            // Only if there was a change, we update the control data, otherwise leave it NULL.
            if (_read_control_data_from_subscription(_control_data, already_active)) {
                *control_data = &_control_data;
            }
        }
    }

    return 0;
}

bool InputRC::_read_control_data_from_subscription(ControlData &control_data, bool already_active)
{
    manual_control_setpoint_s manual_control_setpoint;
    orb_copy(ORB_ID(manual_control_setpoint), _manual_control_setpoint_sub, &manual_control_setpoint);
    control_data.type = ControlData::Type::Angle;

    float new_aux_values[3];

    for (int i = 0; i < 3; ++i) {
        new_aux_values[i] = _get_aux_value(manual_control_setpoint, i);
    }

    // If we were already active previously, we just update normally. Otherwise, there needs to be
    // a major stick movement to re-activate manual (or it's running for the very first time).
    bool major_movement = false;

    // Detect a big stick movement
    for (int i = 0; i < 3; ++i) {
        if (fabsf(_last_set_aux_values[i] - new_aux_values[i]) > 0.25f) {
            major_movement = true;
        }
    }

    if (already_active || major_movement || _first_time) {

        _first_time = false;

        for (int i = 0; i < 3; ++i) {
            control_data.type_data.angle.is_speed[i] = false;
            control_data.type_data.angle.angles[i] = new_aux_values[i] * M_PI_F;
            control_data.stabilize_axis[i] = _do_stabilization;

            _last_set_aux_values[i] = new_aux_values[i];
        }

        control_data.gimbal_shutter_retract = false;
        return true;

    } else {
        return false;
    }
}

float InputRC::_get_aux_value(const manual_control_setpoint_s &manual_control_setpoint, int channel_idx)
{
    switch (_aux_channels[channel_idx]) {

    case 1:
        return manual_control_setpoint.aux1;

    case 2:
        return manual_control_setpoint.aux2;

    case 3:
        return manual_control_setpoint.aux3;

    case 4:
        return manual_control_setpoint.aux4;

    case 5:
        return manual_control_setpoint.aux5;

    case 6:
        return manual_control_setpoint.aux6;

    default:
        return 0.0f;
    }
}

void InputRC::print_status()
{
    PX4_INFO("Input: RC (channels: roll=%i, pitch=%i, yaw=%i)", _aux_channels[0], _aux_channels[1], _aux_channels[2]);
}

} /* namespace vmount */