ardupilot/ArduCopter/GCS_Mavlink.cpp

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

#include "Copter.h"

// default sensors are present and healthy: gyro, accelerometer, barometer, rate_control, attitude_stabilization, yaw_position, altitude control, x/y position control, motor_control
#define MAVLINK_SENSOR_PRESENT_DEFAULT (MAV_SYS_STATUS_SENSOR_3D_GYRO | MAV_SYS_STATUS_SENSOR_3D_ACCEL | MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE | MAV_SYS_STATUS_SENSOR_ANGULAR_RATE_CONTROL | MAV_SYS_STATUS_SENSOR_ATTITUDE_STABILIZATION | MAV_SYS_STATUS_SENSOR_YAW_POSITION | MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL | MAV_SYS_STATUS_SENSOR_XY_POSITION_CONTROL | MAV_SYS_STATUS_SENSOR_MOTOR_OUTPUTS | MAV_SYS_STATUS_AHRS)

void Copter::gcs_send_heartbeat(void)
{
    gcs_send_message(MSG_HEARTBEAT);
}

void Copter::gcs_send_deferred(void)
{
    gcs_send_message(MSG_RETRY_DEFERRED);
}

/*
 *  !!NOTE!!
 *
 *  the use of NOINLINE separate functions for each message type avoids
 *  a compiler bug in gcc that would cause it to use far more stack
 *  space than is needed. Without the NOINLINE we use the sum of the
 *  stack needed for each message type. Please be careful to follow the
 *  pattern below when adding any new messages
 */

NOINLINE void Copter::send_heartbeat(mavlink_channel_t chan)
{
    uint8_t base_mode = MAV_MODE_FLAG_CUSTOM_MODE_ENABLED;
    uint8_t system_status = ap.land_complete ? MAV_STATE_STANDBY : MAV_STATE_ACTIVE;
    uint32_t custom_mode = control_mode;

    // set system as critical if any failsafe have triggered
    if (failsafe.radio || failsafe.battery || failsafe.gcs || failsafe.ekf)  {
        system_status = MAV_STATE_CRITICAL;
    }

    // work out the base_mode. This value is not very useful
    // for APM, but we calculate it as best we can so a generic
    // MAVLink enabled ground station can work out something about
    // what the MAV is up to. The actual bit values are highly
    // ambiguous for most of the APM flight modes. In practice, you
    // only get useful information from the custom_mode, which maps to
    // the APM flight mode and has a well defined meaning in the
    // ArduPlane documentation
    base_mode = MAV_MODE_FLAG_STABILIZE_ENABLED;
    switch (control_mode) {
    case AUTO:
    case RTL:
    case LOITER:
    case GUIDED:
    case CIRCLE:
    case POSHOLD:
    case BRAKE:
        base_mode |= MAV_MODE_FLAG_GUIDED_ENABLED;
        // note that MAV_MODE_FLAG_AUTO_ENABLED does not match what
        // APM does in any mode, as that is defined as "system finds its own goal
        // positions", which APM does not currently do
        break;
    }

    // all modes except INITIALISING have some form of manual
    // override if stick mixing is enabled
    base_mode |= MAV_MODE_FLAG_MANUAL_INPUT_ENABLED;

#if HIL_MODE != HIL_MODE_DISABLED
    base_mode |= MAV_MODE_FLAG_HIL_ENABLED;
#endif

    // we are armed if we are not initialising
    if (motors.armed()) {
        base_mode |= MAV_MODE_FLAG_SAFETY_ARMED;
    }

    // indicate we have set a custom mode
    base_mode |= MAV_MODE_FLAG_CUSTOM_MODE_ENABLED;

    mavlink_msg_heartbeat_send(
        chan,
#if (FRAME_CONFIG == QUAD_FRAME)
        MAV_TYPE_QUADROTOR,
#elif (FRAME_CONFIG == TRI_FRAME)
        MAV_TYPE_TRICOPTER,
#elif (FRAME_CONFIG == HEXA_FRAME || FRAME_CONFIG == Y6_FRAME)
        MAV_TYPE_HEXAROTOR,
#elif (FRAME_CONFIG == OCTA_FRAME || FRAME_CONFIG == OCTA_QUAD_FRAME)
        MAV_TYPE_OCTOROTOR,
#elif (FRAME_CONFIG == HELI_FRAME)
        MAV_TYPE_HELICOPTER,
#elif (FRAME_CONFIG == SINGLE_FRAME)  //because mavlink did not define a singlecopter, we use a rocket
        MAV_TYPE_ROCKET,
#elif (FRAME_CONFIG == COAX_FRAME)  //because mavlink did not define a singlecopter, we use a rocket
        MAV_TYPE_ROCKET,
#else
  #error Unrecognised frame type
#endif
        MAV_AUTOPILOT_ARDUPILOTMEGA,
        base_mode,
        custom_mode,
        system_status);
}

NOINLINE void Copter::send_attitude(mavlink_channel_t chan)
{
    const Vector3f &gyro = ins.get_gyro();
    mavlink_msg_attitude_send(
        chan,
        millis(),
        ahrs.roll,
        ahrs.pitch,
        ahrs.yaw,
        gyro.x,
        gyro.y,
        gyro.z);
}

#if AC_FENCE == ENABLED
NOINLINE void Copter::send_limits_status(mavlink_channel_t chan)
{
    fence_send_mavlink_status(chan);
}
#endif


NOINLINE void Copter::send_extended_status1(mavlink_channel_t chan)
{
    uint32_t control_sensors_present;
    uint32_t control_sensors_enabled;
    uint32_t control_sensors_health;

    // default sensors present
    control_sensors_present = MAVLINK_SENSOR_PRESENT_DEFAULT;

    // first what sensors/controllers we have
    if (g.compass_enabled) {
        control_sensors_present |= MAV_SYS_STATUS_SENSOR_3D_MAG; // compass present
    }
    if (gps.status() > AP_GPS::NO_GPS) {
        control_sensors_present |= MAV_SYS_STATUS_SENSOR_GPS;
    }
#if OPTFLOW == ENABLED
    if (optflow.enabled()) {
        control_sensors_present |= MAV_SYS_STATUS_SENSOR_OPTICAL_FLOW;
    }
#endif
    if (ap.rc_receiver_present) {
        control_sensors_present |= MAV_SYS_STATUS_SENSOR_RC_RECEIVER;
    }

    // all present sensors enabled by default except altitude and position control and motors which we will set individually
    control_sensors_enabled = control_sensors_present & (~MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL &
                                                         ~MAV_SYS_STATUS_SENSOR_XY_POSITION_CONTROL &
                                                         ~MAV_SYS_STATUS_SENSOR_MOTOR_OUTPUTS);

    switch (control_mode) {
    case ALT_HOLD:
    case AUTO:
    case GUIDED:
    case LOITER:
    case RTL:
    case CIRCLE:
    case LAND:
    case OF_LOITER:
    case POSHOLD:
    case BRAKE:
        control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL;
        control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_XY_POSITION_CONTROL;
        break;
    case SPORT:
        control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL;
        break;
    }

    // set motors outputs as enabled if safety switch is not disarmed (i.e. either NONE or ARMED)
    if (hal.util->safety_switch_state() != AP_HAL::Util::SAFETY_DISARMED) {
        control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_MOTOR_OUTPUTS;
    }

    // default to all healthy except baro, compass, gps and receiver which we set individually
    control_sensors_health = control_sensors_present & ~(MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE |
                                                         MAV_SYS_STATUS_SENSOR_3D_MAG |
                                                         MAV_SYS_STATUS_SENSOR_GPS |
                                                         MAV_SYS_STATUS_SENSOR_RC_RECEIVER);
    if (barometer.all_healthy()) {
        control_sensors_health |= MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE;
    }
    if (g.compass_enabled && compass.healthy() && ahrs.use_compass()) {
        control_sensors_health |= MAV_SYS_STATUS_SENSOR_3D_MAG;
    }
    if (gps.status() > AP_GPS::NO_GPS) {
        control_sensors_health |= MAV_SYS_STATUS_SENSOR_GPS;
    }
#if OPTFLOW == ENABLED
    if (optflow.healthy()) {
        control_sensors_health |= MAV_SYS_STATUS_SENSOR_OPTICAL_FLOW;
    }
#endif
    if (ap.rc_receiver_present && !failsafe.radio) {
        control_sensors_health |= MAV_SYS_STATUS_SENSOR_RC_RECEIVER;
    }
    if (!ins.get_gyro_health_all() || !ins.gyro_calibrated_ok_all()) {
        control_sensors_health &= ~MAV_SYS_STATUS_SENSOR_3D_GYRO;
    }
    if (!ins.get_accel_health_all()) {
        control_sensors_health &= ~MAV_SYS_STATUS_SENSOR_3D_ACCEL;
    }

    if (ahrs.initialised() && !ahrs.healthy()) {
        // AHRS subsystem is unhealthy
        control_sensors_health &= ~MAV_SYS_STATUS_AHRS;
    }

    int16_t battery_current = -1;
    int8_t battery_remaining = -1;

    if (battery.has_current() && battery.healthy()) {
        battery_remaining = battery.capacity_remaining_pct();
        battery_current = battery.current_amps() * 100;
    }

#if AP_TERRAIN_AVAILABLE
    switch (terrain.status()) {
    case AP_Terrain::TerrainStatusDisabled:
        break;
    case AP_Terrain::TerrainStatusUnhealthy:
        // To-Do: restore unhealthy terrain status reporting once terrain is used in copter
        //control_sensors_present |= MAV_SYS_STATUS_TERRAIN;
        //control_sensors_enabled |= MAV_SYS_STATUS_TERRAIN;
        //break;
    case AP_Terrain::TerrainStatusOK:
        control_sensors_present |= MAV_SYS_STATUS_TERRAIN;
        control_sensors_enabled |= MAV_SYS_STATUS_TERRAIN;
        control_sensors_health  |= MAV_SYS_STATUS_TERRAIN;
        break;
    }
#endif

#if CONFIG_SONAR == ENABLED
    if (sonar.num_sensors() > 0) {
        control_sensors_present |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
        control_sensors_enabled |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
        if (sonar.has_data()) {
            control_sensors_health |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
        }
    }
#endif

    if (!ap.initialised || ins.calibrating()) {
        // while initialising the gyros and accels are not enabled
        control_sensors_enabled &= ~(MAV_SYS_STATUS_SENSOR_3D_GYRO | MAV_SYS_STATUS_SENSOR_3D_ACCEL);
        control_sensors_health &= ~(MAV_SYS_STATUS_SENSOR_3D_GYRO | MAV_SYS_STATUS_SENSOR_3D_ACCEL);
    }

    mavlink_msg_sys_status_send(
        chan,
        control_sensors_present,
        control_sensors_enabled,
        control_sensors_health,
        (uint16_t)(scheduler.load_average(MAIN_LOOP_MICROS) * 1000),
        battery.voltage() * 1000, // mV
        battery_current,        // in 10mA units
        battery_remaining,      // in %
        0, // comm drops %,
        0, // comm drops in pkts,
        0, 0, 0, 0);

}

void NOINLINE Copter::send_location(mavlink_channel_t chan)
{
    uint32_t fix_time;
    // if we have a GPS fix, take the time as the last fix time. That
    // allows us to correctly calculate velocities and extrapolate
    // positions.
    // If we don't have a GPS fix then we are dead reckoning, and will
    // use the current boot time as the fix time.
    if (gps.status() >= AP_GPS::GPS_OK_FIX_2D) {
        fix_time = gps.last_fix_time_ms();
    } else {
        fix_time = millis();
    }
    const Vector3f &vel = inertial_nav.get_velocity();
    mavlink_msg_global_position_int_send(
        chan,
        fix_time,
        current_loc.lat,                // in 1E7 degrees
        current_loc.lng,                // in 1E7 degrees
        (ahrs.get_home().alt + current_loc.alt) * 10UL,      // millimeters above sea level
        current_loc.alt * 10,           // millimeters above ground
        vel.x,                          // X speed cm/s (+ve North)
        vel.y,                          // Y speed cm/s (+ve East)
        vel.z,                          // Z speed cm/s (+ve up)
        ahrs.yaw_sensor);               // compass heading in 1/100 degree
}

void NOINLINE Copter::send_nav_controller_output(mavlink_channel_t chan)
{
    const Vector3f &targets = attitude_control.angle_ef_targets();
    mavlink_msg_nav_controller_output_send(
        chan,
        targets.x / 1.0e2f,
        targets.y / 1.0e2f,
        targets.z / 1.0e2f,
        wp_bearing / 1.0e2f,
        wp_distance / 1.0e2f,
        pos_control.get_alt_error() / 1.0e2f,
        0,
        0);
}

// report simulator state
void NOINLINE Copter::send_simstate(mavlink_channel_t chan)
{
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
    sitl.simstate_send(chan);
#endif
}

void NOINLINE Copter::send_hwstatus(mavlink_channel_t chan)
{
    mavlink_msg_hwstatus_send(
        chan,
        hal.analogin->board_voltage()*1000,
        hal.i2c->lockup_count());
}

void NOINLINE Copter::send_servo_out(mavlink_channel_t chan)
{
#if HIL_MODE != HIL_MODE_DISABLED
    // normalized values scaled to -10000 to 10000
    // This is used for HIL.  Do not change without discussing with HIL maintainers

#if FRAME_CONFIG == HELI_FRAME
    mavlink_msg_rc_channels_scaled_send(
        chan,
        millis(),
        0, // port 0
        g.rc_1.servo_out,
        g.rc_2.servo_out,
        g.rc_3.radio_out,
        g.rc_4.servo_out,
        0,
        0,
        0,
        0,
        receiver_rssi);
#else
    mavlink_msg_rc_channels_scaled_send(
        chan,
        millis(),
        0,         // port 0
        g.rc_1.servo_out,
        g.rc_2.servo_out,
        g.rc_3.radio_out,
        g.rc_4.servo_out,
        10000 * g.rc_1.norm_output(),
        10000 * g.rc_2.norm_output(),
        10000 * g.rc_3.norm_output(),
        10000 * g.rc_4.norm_output(),
        receiver_rssi);
#endif
#endif // HIL_MODE
}

void NOINLINE Copter::send_radio_out(mavlink_channel_t chan)
{
    mavlink_msg_servo_output_raw_send(
        chan,
        micros(),
        0,     // port
        hal.rcout->read(0),
        hal.rcout->read(1),
        hal.rcout->read(2),
        hal.rcout->read(3),
        hal.rcout->read(4),
        hal.rcout->read(5),
        hal.rcout->read(6),
        hal.rcout->read(7));
}

void NOINLINE Copter::send_vfr_hud(mavlink_channel_t chan)
{
    mavlink_msg_vfr_hud_send(
        chan,
        gps.ground_speed(),
        gps.ground_speed(),
        (ahrs.yaw_sensor / 100) % 360,
        (int16_t)(motors.get_throttle())/10,
        current_loc.alt / 100.0f,
        climb_rate / 100.0f);
}

void NOINLINE Copter::send_current_waypoint(mavlink_channel_t chan)
{
    mavlink_msg_mission_current_send(chan, mission.get_current_nav_index());
}

#if CONFIG_SONAR == ENABLED
void NOINLINE Copter::send_rangefinder(mavlink_channel_t chan)
{
    // exit immediately if sonar is disabled
    if (!sonar.has_data()) {
        return;
    }
    mavlink_msg_rangefinder_send(
            chan,
            sonar.distance_cm() * 0.01f,
            sonar.voltage_mv() * 0.001f);
}
#endif

/*
  send RPM packet
 */
void NOINLINE Copter::send_rpm(mavlink_channel_t chan)
{
    if (rpm_sensor.healthy(0) || rpm_sensor.healthy(1)) {
        mavlink_msg_rpm_send(
            chan,
            rpm_sensor.get_rpm(0),
            rpm_sensor.get_rpm(1));
    }
}


/*
  send PID tuning message
 */
void Copter::send_pid_tuning(mavlink_channel_t chan)
{
    const Vector3f &gyro = ahrs.get_gyro();
    if (g.gcs_pid_mask & 1) {
        const DataFlash_Class::PID_Info &pid_info = g.pid_rate_roll.get_pid_info();
        mavlink_msg_pid_tuning_send(chan, PID_TUNING_ROLL, 
                                    pid_info.desired*0.01f,
                                    degrees(gyro.x),
                                    pid_info.FF*0.01f,
                                    pid_info.P*0.01f,
                                    pid_info.I*0.01f,
                                    pid_info.D*0.01f);
        if (!HAVE_PAYLOAD_SPACE(chan, PID_TUNING)) {
            return;
        }
    }
    if (g.gcs_pid_mask & 2) {
        const DataFlash_Class::PID_Info &pid_info = g.pid_rate_pitch.get_pid_info();
        mavlink_msg_pid_tuning_send(chan, PID_TUNING_PITCH, 
                                    pid_info.desired*0.01f,
                                    degrees(gyro.y),
                                    pid_info.FF*0.01f,
                                    pid_info.P*0.01f,
                                    pid_info.I*0.01f,
                                    pid_info.D*0.01f);
        if (!HAVE_PAYLOAD_SPACE(chan, PID_TUNING)) {
            return;
        }
    }
    if (g.gcs_pid_mask & 4) {
        const DataFlash_Class::PID_Info &pid_info = g.pid_rate_yaw.get_pid_info();
        mavlink_msg_pid_tuning_send(chan, PID_TUNING_YAW, 
                                    pid_info.desired*0.01f,
                                    degrees(gyro.z),
                                    pid_info.FF*0.01f,
                                    pid_info.P*0.01f,
                                    pid_info.I*0.01f,
                                    pid_info.D*0.01f);
        if (!HAVE_PAYLOAD_SPACE(chan, PID_TUNING)) {
            return;
        }
    }
    if (g.gcs_pid_mask & 8) {
        const DataFlash_Class::PID_Info &pid_info = g.pid_accel_z.get_pid_info();
        mavlink_msg_pid_tuning_send(chan, PID_TUNING_ACCZ, 
                                    pid_info.desired*0.01f,
                                    -(ahrs.get_accel_ef_blended().z + GRAVITY_MSS),
                                    pid_info.FF*0.01f,
                                    pid_info.P*0.01f,
                                    pid_info.I*0.01f,
                                    pid_info.D*0.01f);
        if (!HAVE_PAYLOAD_SPACE(chan, PID_TUNING)) {
            return;
        }
    }
}


void NOINLINE Copter::send_statustext(mavlink_channel_t chan)
{
    mavlink_statustext_t *s = &gcs[chan-MAVLINK_COMM_0].pending_status;
    mavlink_msg_statustext_send(
        chan,
        s->severity,
        s->text);
}

// are we still delaying telemetry to try to avoid Xbee bricking?
bool Copter::telemetry_delayed(mavlink_channel_t chan)
{
    uint32_t tnow = millis() >> 10;
    if (tnow > (uint32_t)g.telem_delay) {
        return false;
    }
    if (chan == MAVLINK_COMM_0 && hal.gpio->usb_connected()) {
        // this is USB telemetry, so won't be an Xbee
        return false;
    }
    // we're either on the 2nd UART, or no USB cable is connected
    // we need to delay telemetry by the TELEM_DELAY time
    return true;
}


// try to send a message, return false if it won't fit in the serial tx buffer
bool GCS_MAVLINK::try_send_message(enum ap_message id)
{
    if (copter.telemetry_delayed(chan)) {
        return false;
    }

#if HIL_MODE != HIL_MODE_SENSORS
    // if we don't have at least 250 micros remaining before the main loop
    // wants to fire then don't send a mavlink message. We want to
    // prioritise the main flight control loop over communications
    if (copter.scheduler.time_available_usec() < 250 && copter.motors.armed()) {
        copter.gcs_out_of_time = true;
        return false;
    }
#endif

    switch(id) {
    case MSG_HEARTBEAT:
        CHECK_PAYLOAD_SIZE(HEARTBEAT);
        copter.gcs[chan-MAVLINK_COMM_0].last_heartbeat_time = hal.scheduler->millis();
        copter.send_heartbeat(chan);
        break;

    case MSG_EXTENDED_STATUS1:
        // send extended status only once vehicle has been initialised
        // to avoid unnecessary errors being reported to user
        if (copter.ap.initialised) {
            CHECK_PAYLOAD_SIZE(SYS_STATUS);
            copter.send_extended_status1(chan);
            CHECK_PAYLOAD_SIZE(POWER_STATUS);
            copter.gcs[chan-MAVLINK_COMM_0].send_power_status();
        }
        break;

    case MSG_EXTENDED_STATUS2:
        CHECK_PAYLOAD_SIZE(MEMINFO);
        copter.gcs[chan-MAVLINK_COMM_0].send_meminfo();
        break;

    case MSG_ATTITUDE:
        CHECK_PAYLOAD_SIZE(ATTITUDE);
        copter.send_attitude(chan);
        break;

    case MSG_LOCATION:
        CHECK_PAYLOAD_SIZE(GLOBAL_POSITION_INT);
        copter.send_location(chan);
        break;

    case MSG_LOCAL_POSITION:
        CHECK_PAYLOAD_SIZE(LOCAL_POSITION_NED);
        send_local_position(copter.ahrs);
        break;

    case MSG_NAV_CONTROLLER_OUTPUT:
        CHECK_PAYLOAD_SIZE(NAV_CONTROLLER_OUTPUT);
        copter.send_nav_controller_output(chan);
        break;

    case MSG_GPS_RAW:
        return copter.gcs[chan-MAVLINK_COMM_0].send_gps_raw(copter.gps);

    case MSG_SYSTEM_TIME:
        CHECK_PAYLOAD_SIZE(SYSTEM_TIME);
        copter.gcs[chan-MAVLINK_COMM_0].send_system_time(copter.gps);
        break;

    case MSG_SERVO_OUT:
        CHECK_PAYLOAD_SIZE(RC_CHANNELS_SCALED);
        copter.send_servo_out(chan);
        break;

    case MSG_RADIO_IN:
        CHECK_PAYLOAD_SIZE(RC_CHANNELS_RAW);
        copter.gcs[chan-MAVLINK_COMM_0].send_radio_in(copter.receiver_rssi);
        break;

    case MSG_RADIO_OUT:
        CHECK_PAYLOAD_SIZE(SERVO_OUTPUT_RAW);
        copter.send_radio_out(chan);
        break;

    case MSG_VFR_HUD:
        CHECK_PAYLOAD_SIZE(VFR_HUD);
        copter.send_vfr_hud(chan);
        break;

    case MSG_RAW_IMU1:
        CHECK_PAYLOAD_SIZE(RAW_IMU);
        copter.gcs[chan-MAVLINK_COMM_0].send_raw_imu(copter.ins, copter.compass);
        break;

    case MSG_RAW_IMU2:
        CHECK_PAYLOAD_SIZE(SCALED_PRESSURE);
        copter.gcs[chan-MAVLINK_COMM_0].send_scaled_pressure(copter.barometer);
        break;

    case MSG_RAW_IMU3:
        CHECK_PAYLOAD_SIZE(SENSOR_OFFSETS);
        copter.gcs[chan-MAVLINK_COMM_0].send_sensor_offsets(copter.ins, copter.compass, copter.barometer);
        break;

    case MSG_CURRENT_WAYPOINT:
        CHECK_PAYLOAD_SIZE(MISSION_CURRENT);
        copter.send_current_waypoint(chan);
        break;

    case MSG_NEXT_PARAM:
        CHECK_PAYLOAD_SIZE(PARAM_VALUE);
        copter.gcs[chan-MAVLINK_COMM_0].queued_param_send();
        break;

    case MSG_NEXT_WAYPOINT:
        CHECK_PAYLOAD_SIZE(MISSION_REQUEST);
        copter.gcs[chan-MAVLINK_COMM_0].queued_waypoint_send();
        break;

    case MSG_RANGEFINDER:
#if CONFIG_SONAR == ENABLED
        CHECK_PAYLOAD_SIZE(RANGEFINDER);
        copter.send_rangefinder(chan);
#endif
        break;

    case MSG_RPM:
        CHECK_PAYLOAD_SIZE(RPM);
        copter.send_rpm(chan);
        break;

    case MSG_TERRAIN:
#if AP_TERRAIN_AVAILABLE
        CHECK_PAYLOAD_SIZE(TERRAIN_REQUEST);
        copter.terrain.send_request(chan);
#endif
        break;

    case MSG_CAMERA_FEEDBACK:
#if CAMERA == ENABLED
        CHECK_PAYLOAD_SIZE(CAMERA_FEEDBACK);
        copter.camera.send_feedback(chan, copter.gps, copter.ahrs, copter.current_loc);
#endif
        break;

    case MSG_STATUSTEXT:
        CHECK_PAYLOAD_SIZE(STATUSTEXT);
        copter.send_statustext(chan);
        break;

    case MSG_LIMITS_STATUS:
#if AC_FENCE == ENABLED
        CHECK_PAYLOAD_SIZE(LIMITS_STATUS);
        copter.send_limits_status(chan);
#endif
        break;

    case MSG_AHRS:
        CHECK_PAYLOAD_SIZE(AHRS);
        copter.gcs[chan-MAVLINK_COMM_0].send_ahrs(copter.ahrs);
        break;

    case MSG_SIMSTATE:
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
        CHECK_PAYLOAD_SIZE(SIMSTATE);
        copter.send_simstate(chan);
#endif
        CHECK_PAYLOAD_SIZE(AHRS2);
        copter.gcs[chan-MAVLINK_COMM_0].send_ahrs2(copter.ahrs);
        break;

    case MSG_HWSTATUS:
        CHECK_PAYLOAD_SIZE(HWSTATUS);
        copter.send_hwstatus(chan);
        break;

    case MSG_MOUNT_STATUS:
#if MOUNT == ENABLED
        CHECK_PAYLOAD_SIZE(MOUNT_STATUS);    
        copter.camera_mount.status_msg(chan);
#endif // MOUNT == ENABLED
        break;

    case MSG_BATTERY2:
        CHECK_PAYLOAD_SIZE(BATTERY2);
        copter.gcs[chan-MAVLINK_COMM_0].send_battery2(copter.battery);
        break;

    case MSG_OPTICAL_FLOW:
#if OPTFLOW == ENABLED
        CHECK_PAYLOAD_SIZE(OPTICAL_FLOW);
        copter.gcs[chan-MAVLINK_COMM_0].send_opticalflow(copter.ahrs, copter.optflow);
#endif
        break;

    case MSG_GIMBAL_REPORT:
#if MOUNT == ENABLED
        CHECK_PAYLOAD_SIZE(GIMBAL_REPORT);
        copter.camera_mount.send_gimbal_report(chan);
#endif
        break;

    case MSG_EKF_STATUS_REPORT:
        CHECK_PAYLOAD_SIZE(EKF_STATUS_REPORT);
        copter.ahrs.get_NavEKF().send_status_report(chan);
        break;

    case MSG_FENCE_STATUS:
    case MSG_WIND:
        // unused
        break;

    case MSG_PID_TUNING:
        CHECK_PAYLOAD_SIZE(PID_TUNING);
        copter.send_pid_tuning(chan);
        break;

    case MSG_VIBRATION:
        CHECK_PAYLOAD_SIZE(VIBRATION);
        send_vibration(copter.ins);
        break;

    case MSG_MISSION_ITEM_REACHED:
        CHECK_PAYLOAD_SIZE(MISSION_ITEM_REACHED);
        mavlink_msg_mission_item_reached_send(chan, mission_item_reached_index);
        break;

    case MSG_RETRY_DEFERRED:
        break; // just here to prevent a warning

    case MSG_MAG_CAL_PROGRESS:
        copter.compass.send_mag_cal_progress(chan);
        break;

    case MSG_MAG_CAL_REPORT:
        copter.compass.send_mag_cal_report(chan);
        break;
    }

    return true;
}


const AP_Param::GroupInfo GCS_MAVLINK::var_info[] PROGMEM = {
    // @Param: RAW_SENS
    // @DisplayName: Raw sensor stream rate
    // @Description: Stream rate of RAW_IMU, SCALED_IMU2, SCALED_PRESSURE, and SENSOR_OFFSETS to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("RAW_SENS", 0, GCS_MAVLINK, streamRates[0],  0),

    // @Param: EXT_STAT
    // @DisplayName: Extended status stream rate to ground station
    // @Description: Stream rate of SYS_STATUS, MEMINFO, MISSION_CURRENT, GPS_RAW_INT, NAV_CONTROLLER_OUTPUT, and LIMITS_STATUS to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("EXT_STAT", 1, GCS_MAVLINK, streamRates[1],  0),

    // @Param: RC_CHAN
    // @DisplayName: RC Channel stream rate to ground station
    // @Description: Stream rate of SERVO_OUTPUT_RAW and RC_CHANNELS_RAW to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("RC_CHAN",  2, GCS_MAVLINK, streamRates[2],  0),

    // @Param: RAW_CTRL
    // @DisplayName: Raw Control stream rate to ground station
    // @Description: Stream rate of RC_CHANNELS_SCALED (HIL only) to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("RAW_CTRL", 3, GCS_MAVLINK, streamRates[3],  0),

    // @Param: POSITION
    // @DisplayName: Position stream rate to ground station
    // @Description: Stream rate of GLOBAL_POSITION_INT to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("POSITION", 4, GCS_MAVLINK, streamRates[4],  0),

    // @Param: EXTRA1
    // @DisplayName: Extra data type 1 stream rate to ground station
    // @Description: Stream rate of ATTITUDE and SIMSTATE (SITL only) to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("EXTRA1",   5, GCS_MAVLINK, streamRates[5],  0),

    // @Param: EXTRA2
    // @DisplayName: Extra data type 2 stream rate to ground station
    // @Description: Stream rate of VFR_HUD to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("EXTRA2",   6, GCS_MAVLINK, streamRates[6],  0),

    // @Param: EXTRA3
    // @DisplayName: Extra data type 3 stream rate to ground station
    // @Description: Stream rate of AHRS, HWSTATUS, and SYSTEM_TIME to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("EXTRA3",   7, GCS_MAVLINK, streamRates[7],  0),

    // @Param: PARAMS
    // @DisplayName: Parameter stream rate to ground station
    // @Description: Stream rate of PARAM_VALUE to ground station
    // @Units: Hz
    // @Range: 0 10
    // @Increment: 1
    // @User: Advanced
    AP_GROUPINFO("PARAMS",   8, GCS_MAVLINK, streamRates[8],  0),
    AP_GROUPEND
};


// see if we should send a stream now. Called at 50Hz
bool GCS_MAVLINK::stream_trigger(enum streams stream_num)
{
    if (stream_num >= NUM_STREAMS) {
        return false;
    }
    float rate = (uint8_t)streamRates[stream_num].get();

    // send at a much lower rate while handling waypoints and
    // parameter sends
    if ((stream_num != STREAM_PARAMS) &&
        (waypoint_receiving || _queued_parameter != NULL)) {
        rate *= 0.25f;
    }

    if (rate <= 0) {
        return false;
    }

    if (stream_ticks[stream_num] == 0) {
        // we're triggering now, setup the next trigger point
        if (rate > 50) {
            rate = 50;
        }
        stream_ticks[stream_num] = (50 / rate) - 1 + stream_slowdown;
        return true;
    }

    // count down at 50Hz
    stream_ticks[stream_num]--;
    return false;
}

void
GCS_MAVLINK::data_stream_send(void)
{
    if (waypoint_receiving) {
        // don't interfere with mission transfer
        return;
    }

    if (!copter.in_mavlink_delay && !copter.motors.armed()) {
        handle_log_send(copter.DataFlash);
    }

    copter.gcs_out_of_time = false;

    if (_queued_parameter != NULL) {
        if (streamRates[STREAM_PARAMS].get() <= 0) {
            streamRates[STREAM_PARAMS].set(10);
        }
        if (stream_trigger(STREAM_PARAMS)) {
            send_message(MSG_NEXT_PARAM);
        }
        // don't send anything else at the same time as parameters
        return;
    }

    if (copter.gcs_out_of_time) return;

    if (copter.in_mavlink_delay) {
        // don't send any other stream types while in the delay callback
        return;
    }

    if (stream_trigger(STREAM_RAW_SENSORS)) {
        send_message(MSG_RAW_IMU1);
        send_message(MSG_RAW_IMU2);
        send_message(MSG_RAW_IMU3);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_EXTENDED_STATUS)) {
        send_message(MSG_EXTENDED_STATUS1);
        send_message(MSG_EXTENDED_STATUS2);
        send_message(MSG_CURRENT_WAYPOINT);
        send_message(MSG_GPS_RAW);
        send_message(MSG_NAV_CONTROLLER_OUTPUT);
        send_message(MSG_LIMITS_STATUS);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_POSITION)) {
        send_message(MSG_LOCATION);
        send_message(MSG_LOCAL_POSITION);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_RAW_CONTROLLER)) {
        send_message(MSG_SERVO_OUT);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_RC_CHANNELS)) {
        send_message(MSG_RADIO_OUT);
        send_message(MSG_RADIO_IN);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_EXTRA1)) {
        send_message(MSG_ATTITUDE);
        send_message(MSG_SIMSTATE);
        send_message(MSG_PID_TUNING);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_EXTRA2)) {
        send_message(MSG_VFR_HUD);
    }

    if (copter.gcs_out_of_time) return;

    if (stream_trigger(STREAM_EXTRA3)) {
        send_message(MSG_AHRS);
        send_message(MSG_HWSTATUS);
        send_message(MSG_SYSTEM_TIME);
        send_message(MSG_RANGEFINDER);
#if AP_TERRAIN_AVAILABLE
        send_message(MSG_TERRAIN);
#endif
        send_message(MSG_BATTERY2);
        send_message(MSG_MOUNT_STATUS);
        send_message(MSG_OPTICAL_FLOW);
        send_message(MSG_GIMBAL_REPORT);
        send_message(MSG_MAG_CAL_REPORT);
        send_message(MSG_MAG_CAL_PROGRESS);
        send_message(MSG_EKF_STATUS_REPORT);
        send_message(MSG_VIBRATION);
        send_message(MSG_RPM);
    }
}


void GCS_MAVLINK::handle_guided_request(AP_Mission::Mission_Command &cmd)
{
    copter.do_guided(cmd);
}

void GCS_MAVLINK::handle_change_alt_request(AP_Mission::Mission_Command &cmd)
{
    // add home alt if needed
    if (cmd.content.location.flags.relative_alt) {
        cmd.content.location.alt += copter.ahrs.get_home().alt;
    }

    // To-Do: update target altitude for loiter or waypoint controller depending upon nav mode
}

void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
{
    uint8_t result = MAV_RESULT_FAILED;         // assume failure.  Each messages id is responsible for return ACK or NAK if required

    switch (msg->msgid) {

    case MAVLINK_MSG_ID_HEARTBEAT:      // MAV ID: 0
    {
        // We keep track of the last time we received a heartbeat from our GCS for failsafe purposes
        if(msg->sysid != copter.g.sysid_my_gcs) break;
        copter.failsafe.last_heartbeat_ms = hal.scheduler->millis();
        copter.pmTest1++;
        break;
    }

    case MAVLINK_MSG_ID_SET_MODE:       // MAV ID: 11
    {
        handle_set_mode(msg, FUNCTOR_BIND(&copter, &Copter::set_mode, bool, uint8_t));
        break;
    }

    case MAVLINK_MSG_ID_PARAM_REQUEST_READ:         // MAV ID: 20
    {
        handle_param_request_read(msg);
        break;
    }

    case MAVLINK_MSG_ID_PARAM_REQUEST_LIST:         // MAV ID: 21
    {
        // mark the firmware version in the tlog
        send_text_P(MAV_SEVERITY_WARNING, PSTR(FIRMWARE_STRING));

#if defined(PX4_GIT_VERSION) && defined(NUTTX_GIT_VERSION)
        send_text_P(MAV_SEVERITY_WARNING, PSTR("PX4: " PX4_GIT_VERSION " NuttX: " NUTTX_GIT_VERSION));
#endif
        send_text_P(MAV_SEVERITY_WARNING, PSTR("Frame: " FRAME_CONFIG_STRING));
        handle_param_request_list(msg);
        break;
    }

    case MAVLINK_MSG_ID_PARAM_SET:     // 23
    {
        handle_param_set(msg, &copter.DataFlash);
        break;
    }

    case MAVLINK_MSG_ID_MISSION_WRITE_PARTIAL_LIST: // MAV ID: 38
    {
        handle_mission_write_partial_list(copter.mission, msg);
        break;
    }

    // GCS has sent us a mission item, store to EEPROM
    case MAVLINK_MSG_ID_MISSION_ITEM:           // MAV ID: 39
    {
        if (handle_mission_item(msg, copter.mission)) {
            copter.DataFlash.Log_Write_EntireMission(copter.mission);
        }
        break;
    }

    // read an individual command from EEPROM and send it to the GCS
    case MAVLINK_MSG_ID_MISSION_REQUEST:     // MAV ID: 40
    {
        handle_mission_request(copter.mission, msg);
        break;
    }

    case MAVLINK_MSG_ID_MISSION_SET_CURRENT:    // MAV ID: 41
    {
        handle_mission_set_current(copter.mission, msg);
        break;
    }

    // GCS request the full list of commands, we return just the number and leave the GCS to then request each command individually
    case MAVLINK_MSG_ID_MISSION_REQUEST_LIST:       // MAV ID: 43
    {
        handle_mission_request_list(copter.mission, msg);
        break;
    }

    // GCS provides the full number of commands it wishes to upload
    //  individual commands will then be sent from the GCS using the MAVLINK_MSG_ID_MISSION_ITEM message
    case MAVLINK_MSG_ID_MISSION_COUNT:          // MAV ID: 44
    {
        handle_mission_count(copter.mission, msg);
        break;
    }

    case MAVLINK_MSG_ID_MISSION_CLEAR_ALL:      // MAV ID: 45
    {
        handle_mission_clear_all(copter.mission, msg);
        break;
    }

    case MAVLINK_MSG_ID_REQUEST_DATA_STREAM:    // MAV ID: 66
    {
        handle_request_data_stream(msg, false);
        break;
    }

    case MAVLINK_MSG_ID_GIMBAL_REPORT:
    {
#if MOUNT == ENABLED
        handle_gimbal_report(copter.camera_mount, msg);
#endif
        break;
    }

    case MAVLINK_MSG_ID_RC_CHANNELS_OVERRIDE:       // MAV ID: 70
    {
        // allow override of RC channel values for HIL
        // or for complete GCS control of switch position
        // and RC PWM values.
        if(msg->sysid != copter.g.sysid_my_gcs) break;                         // Only accept control from our gcs
        mavlink_rc_channels_override_t packet;
        int16_t v[8];
        mavlink_msg_rc_channels_override_decode(msg, &packet);

        v[0] = packet.chan1_raw;
        v[1] = packet.chan2_raw;
        v[2] = packet.chan3_raw;
        v[3] = packet.chan4_raw;
        v[4] = packet.chan5_raw;
        v[5] = packet.chan6_raw;
        v[6] = packet.chan7_raw;
        v[7] = packet.chan8_raw;

        // record that rc are overwritten so we can trigger a failsafe if we lose contact with groundstation
        copter.failsafe.rc_override_active = hal.rcin->set_overrides(v, 8);

        // a RC override message is considered to be a 'heartbeat' from the ground station for failsafe purposes
        copter.failsafe.last_heartbeat_ms = hal.scheduler->millis();
        break;
    }

    // Pre-Flight calibration requests
    case MAVLINK_MSG_ID_COMMAND_LONG:       // MAV ID: 76
    {
        // decode packet
        mavlink_command_long_t packet;
        mavlink_msg_command_long_decode(msg, &packet);

        switch(packet.command) {

        case MAV_CMD_START_RX_PAIR:
            // initiate bind procedure
            if (!hal.rcin->rc_bind(packet.param1)) {
                result = MAV_RESULT_FAILED;
            } else {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_NAV_TAKEOFF: {
            // param3 : horizontal navigation by pilot acceptable
            // param4 : yaw angle   (not supported)
            // param5 : latitude    (not supported)
            // param6 : longitude   (not supported)
            // param7 : altitude [metres]

            float takeoff_alt = packet.param7 * 100;      // Convert m to cm

            if(copter.do_user_takeoff(takeoff_alt, is_zero(packet.param3))) {
                result = MAV_RESULT_ACCEPTED;
            } else {
                result = MAV_RESULT_FAILED;
            }
            break;
        }


        case MAV_CMD_NAV_LOITER_UNLIM:
            if (copter.set_mode(LOITER)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_NAV_RETURN_TO_LAUNCH:
            if (copter.set_mode(RTL)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_NAV_LAND:
            if (copter.set_mode(LAND)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_CONDITION_YAW:
            // param1 : target angle [0-360]
            // param2 : speed during change [deg per second]
            // param3 : direction (-1:ccw, +1:cw)
            // param4 : relative offset (1) or absolute angle (0)
            if ((packet.param1 >= 0.0f)   &&
            	(packet.param1 <= 360.0f) &&
            	(is_zero(packet.param4) || is_equal(packet.param4,1.0f))) {
            	copter.set_auto_yaw_look_at_heading(packet.param1, packet.param2, (int8_t)packet.param3, (uint8_t)packet.param4);
                result = MAV_RESULT_ACCEPTED;
            } else {
                result = MAV_RESULT_FAILED;
            }
            break;

        case MAV_CMD_DO_CHANGE_SPEED:
            // param1 : unused
            // param2 : new speed in m/s
            // param3 : unused
            // param4 : unused
            if (packet.param2 > 0.0f) {
                copter.wp_nav.set_speed_xy(packet.param2 * 100.0f);
                result = MAV_RESULT_ACCEPTED;
            } else {
                result = MAV_RESULT_FAILED;
            }
            break;

        case MAV_CMD_DO_SET_HOME:
            // param1 : use current (1=use current location, 0=use specified location)
            // param5 : latitude
            // param6 : longitude
            // param7 : altitude (absolute)
            result = MAV_RESULT_FAILED; // assume failure
            if(is_equal(packet.param1,1.0f) || (is_zero(packet.param5) && is_zero(packet.param6) && is_zero(packet.param7))) {
                if (copter.set_home_to_current_location_and_lock()) {
                    result = MAV_RESULT_ACCEPTED;
                }
            } else {
                // sanity check location
                if (fabsf(packet.param5) > 90.0f || fabsf(packet.param6) > 180.0f) {
                    break;
                }
                Location new_home_loc;
                new_home_loc.lat = (int32_t)(packet.param5 * 1.0e7f);
                new_home_loc.lng = (int32_t)(packet.param6 * 1.0e7f);
                new_home_loc.alt = (int32_t)(packet.param7 * 100.0f);
                if (!copter.far_from_EKF_origin(new_home_loc)) {
                    if (copter.set_home_and_lock(new_home_loc)) {
                        result = MAV_RESULT_ACCEPTED;
                    }
                }
            }
            break;

        case MAV_CMD_DO_FLIGHTTERMINATION:
            if (packet.param1 > 0.5f) {
                copter.init_disarm_motors();
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_DO_SET_ROI:
            // param1 : regional of interest mode (not supported)
            // param2 : mission index/ target id (not supported)
            // param3 : ROI index (not supported)
            // param5 : x / lat
            // param6 : y / lon
            // param7 : z / alt
            // sanity check location
            if (fabsf(packet.param5) > 90.0f || fabsf(packet.param6) > 180.0f) {
                break;
            }
            Location roi_loc;
            roi_loc.lat = (int32_t)(packet.param5 * 1.0e7f);
            roi_loc.lng = (int32_t)(packet.param6 * 1.0e7f);
            roi_loc.alt = (int32_t)(packet.param7 * 100.0f);
            copter.set_auto_yaw_roi(roi_loc);
            result = MAV_RESULT_ACCEPTED;
            break;

#if CAMERA == ENABLED
        case MAV_CMD_DO_DIGICAM_CONFIGURE:
            copter.camera.configure(packet.param1,
                                    packet.param2,
                                    packet.param3,
                                    packet.param4,
                                    packet.param5,
                                    packet.param6,
                                    packet.param7);

            result = MAV_RESULT_ACCEPTED;
            break;

        case MAV_CMD_DO_DIGICAM_CONTROL:
            copter.camera.control(packet.param1,
                                  packet.param2,
                                  packet.param3,
                                  packet.param4,
                                  packet.param5,
                                  packet.param6);

            result = MAV_RESULT_ACCEPTED;
            break;
#endif // CAMERA == ENABLED
        case MAV_CMD_DO_MOUNT_CONTROL:
#if MOUNT == ENABLED
            copter.camera_mount.control(packet.param1, packet.param2, packet.param3, (MAV_MOUNT_MODE) packet.param7);
#endif
            break;

        case MAV_CMD_MISSION_START:
            if (copter.motors.armed() && copter.set_mode(AUTO)) {
                copter.set_auto_armed(true);
                if (copter.mission.state() != AP_Mission::MISSION_RUNNING) {
                    copter.mission.start_or_resume();
                }
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_PREFLIGHT_CALIBRATION:
            // exit immediately if armed
            if (copter.motors.armed()) {
                result = MAV_RESULT_FAILED;
                break;
            }
            if (is_equal(packet.param1,1.0f)) {
                // gyro offset calibration
                copter.ins.init_gyro();
                // reset ahrs gyro bias
                if (copter.ins.gyro_calibrated_ok_all()) {
                    copter.ahrs.reset_gyro_drift();
                    result = MAV_RESULT_ACCEPTED;
                } else {
                    result = MAV_RESULT_FAILED;
                }
            } else if (is_equal(packet.param3,1.0f)) {
                // fast barometer calibration
                copter.init_barometer(false);
                result = MAV_RESULT_ACCEPTED;
            } else if (is_equal(packet.param4,1.0f)) {
                result = MAV_RESULT_UNSUPPORTED;
            } else if (is_equal(packet.param5,1.0f)) {
                // 3d accel calibration
                float trim_roll, trim_pitch;
                // this blocks
                AP_InertialSensor_UserInteract_MAVLink interact(this);
                if(copter.ins.calibrate_accel(&interact, trim_roll, trim_pitch)) {
                    // reset ahrs's trim to suggested values from calibration routine
                    copter.ahrs.set_trim(Vector3f(trim_roll, trim_pitch, 0));
                    result = MAV_RESULT_ACCEPTED;
                } else {
                    result = MAV_RESULT_FAILED;
                }
            } else if (is_equal(packet.param5,2.0f)) {
                // accel trim
                float trim_roll, trim_pitch;
                if(copter.ins.calibrate_trim(trim_roll, trim_pitch)) {
                    // reset ahrs's trim to suggested values from calibration routine
                    copter.ahrs.set_trim(Vector3f(trim_roll, trim_pitch, 0));
                    result = MAV_RESULT_ACCEPTED;
                } else {
                    result = MAV_RESULT_FAILED;
                }
            } else if (is_equal(packet.param6,1.0f)) {
                // compassmot calibration
                result = copter.mavlink_compassmot(chan);
            }
            break;

        case MAV_CMD_PREFLIGHT_SET_SENSOR_OFFSETS:
            if (is_equal(packet.param1,2.0f)) {
                // save first compass's offsets
                copter.compass.set_and_save_offsets(0, packet.param2, packet.param3, packet.param4);
                result = MAV_RESULT_ACCEPTED;
            }
            if (is_equal(packet.param1,5.0f)) {
                // save secondary compass's offsets
                copter.compass.set_and_save_offsets(1, packet.param2, packet.param3, packet.param4);
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_COMPONENT_ARM_DISARM:
            if (is_equal(packet.param1,1.0f)) {
                // attempt to arm and return success or failure
                if (copter.init_arm_motors(true)) {
                    result = MAV_RESULT_ACCEPTED;
                }
            } else if (is_zero(packet.param1) && (copter.mode_has_manual_throttle(copter.control_mode) || copter.ap.land_complete || is_equal(packet.param2,21196.0f)))  {
                // force disarming by setting param2 = 21196 is deprecated
                copter.init_disarm_motors();
                result = MAV_RESULT_ACCEPTED;
            } else {
                result = MAV_RESULT_UNSUPPORTED;
            }
            break;

        case MAV_CMD_DO_SET_SERVO:
            if (copter.ServoRelayEvents.do_set_servo(packet.param1, packet.param2)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_DO_REPEAT_SERVO:
            if (copter.ServoRelayEvents.do_repeat_servo(packet.param1, packet.param2, packet.param3, packet.param4*1000)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_DO_SET_RELAY:
            if (copter.ServoRelayEvents.do_set_relay(packet.param1, packet.param2)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_DO_REPEAT_RELAY:
            if (copter.ServoRelayEvents.do_repeat_relay(packet.param1, packet.param2, packet.param3*1000)) {
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_PREFLIGHT_REBOOT_SHUTDOWN:
            if (is_equal(packet.param1,1.0f) || is_equal(packet.param1,3.0f)) {
                AP_Notify::flags.firmware_update = 1;
                copter.update_notify();
                hal.scheduler->delay(200);
                // when packet.param1 == 3 we reboot to hold in bootloader
                hal.scheduler->reboot(is_equal(packet.param1,3.0f));
                result = MAV_RESULT_ACCEPTED;
            }
            break;

        case MAV_CMD_DO_FENCE_ENABLE:
#if AC_FENCE == ENABLED
            result = MAV_RESULT_ACCEPTED;
            switch ((uint16_t)packet.param1) {
                case 0:
                    copter.fence.enable(false);
                    break;
                case 1:
                    copter.fence.enable(true);
                    break;
                default:
                    result = MAV_RESULT_FAILED;
                    break;
            }
#else
            // if fence code is not included return failure
            result = MAV_RESULT_FAILED;
#endif
            break;

#if PARACHUTE == ENABLED
        case MAV_CMD_DO_PARACHUTE:
            // configure or release parachute
            result = MAV_RESULT_ACCEPTED;
            switch ((uint16_t)packet.param1) {
                case PARACHUTE_DISABLE:
                    copter.parachute.enabled(false);
                    copter.Log_Write_Event(DATA_PARACHUTE_DISABLED);
                    break;
                case PARACHUTE_ENABLE:
                    copter.parachute.enabled(true);
                    copter.Log_Write_Event(DATA_PARACHUTE_ENABLED);
                    break;
                case PARACHUTE_RELEASE:
                    // treat as a manual release which performs some additional check of altitude
                    copter.parachute_manual_release();
                    break;
                default:
                    result = MAV_RESULT_FAILED;
                    break;
            }
            break;
#endif

        case MAV_CMD_DO_MOTOR_TEST:
            // param1 : motor sequence number (a number from 1 to max number of motors on the vehicle)
            // param2 : throttle type (0=throttle percentage, 1=PWM, 2=pilot throttle channel pass-through. See MOTOR_TEST_THROTTLE_TYPE enum)
            // param3 : throttle (range depends upon param2)
            // param4 : timeout (in seconds)
            result = copter.mavlink_motor_test_start(chan, (uint8_t)packet.param1, (uint8_t)packet.param2, (uint16_t)packet.param3, packet.param4);
            break;

#if EPM_ENABLED == ENABLED
        case MAV_CMD_DO_GRIPPER:
            // param1 : gripper number (ignored)
            // param2 : action (0=release, 1=grab). See GRIPPER_ACTIONS enum.
            if(!copter.epm.enabled()) {
                result = MAV_RESULT_FAILED;
            } else {
                result = MAV_RESULT_ACCEPTED;
                switch ((uint8_t)packet.param2) {
                    case GRIPPER_ACTION_RELEASE:
                        copter.epm.release();
                        break;
                    case GRIPPER_ACTION_GRAB:
                        copter.epm.grab();
                        break;
                    default:
                        result = MAV_RESULT_FAILED;
                        break;
                }
            }
            break;
#endif

        case MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES: {
            if (is_equal(packet.param1,1.0f)) {
                copter.gcs[chan-MAVLINK_COMM_0].send_autopilot_version(FIRMWARE_VERSION);
                result = MAV_RESULT_ACCEPTED;
            }
            break;
        }

        case MAV_CMD_DO_START_MAG_CAL:
        case MAV_CMD_DO_ACCEPT_MAG_CAL:
        case MAV_CMD_DO_CANCEL_MAG_CAL:
            result = copter.compass.handle_mag_cal_command(packet);

            break;

        default:
            result = MAV_RESULT_UNSUPPORTED;
            break;
        }

        // send ACK or NAK
        mavlink_msg_command_ack_send_buf(msg, chan, packet.command, result);

        break;
    }

    case MAVLINK_MSG_ID_COMMAND_ACK:        // MAV ID: 77
    {
        copter.command_ack_counter++;
        break;
    }

    case MAVLINK_MSG_ID_SET_POSITION_TARGET_LOCAL_NED:     // MAV ID: 84
    {
        // decode packet
        mavlink_set_position_target_local_ned_t packet;
        mavlink_msg_set_position_target_local_ned_decode(msg, &packet);

        // exit if vehicle is not in Guided mode or Auto-Guided mode
        if ((copter.control_mode != GUIDED) && !(copter.control_mode == AUTO && copter.auto_mode == Auto_NavGuided)) {
            break;
        }

        // check for supported coordinate frames
        if (packet.coordinate_frame != MAV_FRAME_LOCAL_NED &&
            packet.coordinate_frame != MAV_FRAME_LOCAL_OFFSET_NED &&
            packet.coordinate_frame != MAV_FRAME_BODY_NED &&
            packet.coordinate_frame != MAV_FRAME_BODY_OFFSET_NED) {
            break;
        }

        bool pos_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_POS_IGNORE;
        bool vel_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_VEL_IGNORE;
        bool acc_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_ACC_IGNORE;

        /*
         * for future use:
         * bool force           = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_FORCE;
         * bool yaw_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_YAW_IGNORE;
         * bool yaw_rate_ignore = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_YAW_RATE_IGNORE;
         */

        // prepare position
        Vector3f pos_vector;
        if (!pos_ignore) {
            // convert to cm
            pos_vector = Vector3f(packet.x * 100.0f, packet.y * 100.0f, -packet.z * 100.0f);
            // rotate to body-frame if necessary
            if (packet.coordinate_frame == MAV_FRAME_BODY_NED ||
                packet.coordinate_frame == MAV_FRAME_BODY_OFFSET_NED) {
                copter.rotate_body_frame_to_NE(pos_vector.x, pos_vector.y);
            }
            // add body offset if necessary
            if (packet.coordinate_frame == MAV_FRAME_LOCAL_OFFSET_NED ||
                packet.coordinate_frame == MAV_FRAME_BODY_NED ||
                packet.coordinate_frame == MAV_FRAME_BODY_OFFSET_NED) {
                pos_vector += copter.inertial_nav.get_position();
            } else {
                // convert from alt-above-home to alt-above-ekf-origin
                pos_vector.z = copter.pv_alt_above_origin(pos_vector.z);
            }
        }

        // prepare velocity
        Vector3f vel_vector;
        if (!vel_ignore) {
            // convert to cm
            vel_vector = Vector3f(packet.vx * 100.0f, packet.vy * 100.0f, -packet.vz * 100.0f);
            // rotate to body-frame if necessary
            if (packet.coordinate_frame == MAV_FRAME_BODY_NED || packet.coordinate_frame == MAV_FRAME_BODY_OFFSET_NED) {
                copter.rotate_body_frame_to_NE(vel_vector.x, vel_vector.y);
            }
        }

        // send request
        if (!pos_ignore && !vel_ignore && acc_ignore) {
            copter.guided_set_destination_posvel(pos_vector, vel_vector);
        } else if (pos_ignore && !vel_ignore && acc_ignore) {
            copter.guided_set_velocity(vel_vector);
        } else if (!pos_ignore && vel_ignore && acc_ignore) {
            copter.guided_set_destination(pos_vector);
        } else {
            result = MAV_RESULT_FAILED;
        }

        break;
    }

    case MAVLINK_MSG_ID_SET_POSITION_TARGET_GLOBAL_INT:    // MAV ID: 86
    {
        // decode packet
        mavlink_set_position_target_global_int_t packet;
        mavlink_msg_set_position_target_global_int_decode(msg, &packet);

        // exit if vehicle is not in Guided mode or Auto-Guided mode
        if ((copter.control_mode != GUIDED) && !(copter.control_mode == AUTO && copter.auto_mode == Auto_NavGuided)) {
            break;
        }

        // check for supported coordinate frames
        if (packet.coordinate_frame != MAV_FRAME_GLOBAL_INT &&
            packet.coordinate_frame != MAV_FRAME_GLOBAL_RELATIVE_ALT_INT &&
            packet.coordinate_frame != MAV_FRAME_GLOBAL_TERRAIN_ALT_INT) {
            break;
        }

        bool pos_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_POS_IGNORE;
        bool vel_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_VEL_IGNORE;
        bool acc_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_ACC_IGNORE;

        /*
         * for future use:
         * bool force           = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_FORCE;
         * bool yaw_ignore      = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_YAW_IGNORE;
         * bool yaw_rate_ignore = packet.type_mask & MAVLINK_SET_POS_TYPE_MASK_YAW_RATE_IGNORE;
         */

        Vector3f pos_ned;

        if(!pos_ignore) {
            Location loc;
            loc.lat = packet.lat_int;
            loc.lng = packet.lon_int;
            loc.alt = packet.alt*100;
            switch (packet.coordinate_frame) {
                case MAV_FRAME_GLOBAL_RELATIVE_ALT_INT:
                    loc.flags.relative_alt = true;
                    loc.flags.terrain_alt = false;
                    break;
                case MAV_FRAME_GLOBAL_TERRAIN_ALT_INT:
                    loc.flags.relative_alt = true;
                    loc.flags.terrain_alt = true;
                    break;
                case MAV_FRAME_GLOBAL_INT:
                default:
                    loc.flags.relative_alt = false;
                    loc.flags.terrain_alt = false;
                    break;
            }
            pos_ned = copter.pv_location_to_vector(loc);
        }

        if (!pos_ignore && !vel_ignore && acc_ignore) {
            copter.guided_set_destination_posvel(pos_ned, Vector3f(packet.vx * 100.0f, packet.vy * 100.0f, -packet.vz * 100.0f));
        } else if (pos_ignore && !vel_ignore && acc_ignore) {
            copter.guided_set_velocity(Vector3f(packet.vx * 100.0f, packet.vy * 100.0f, -packet.vz * 100.0f));
        } else if (!pos_ignore && vel_ignore && acc_ignore) {
            copter.guided_set_destination(pos_ned);
        } else {
            result = MAV_RESULT_FAILED;
        }

        break;
    }

#if HIL_MODE != HIL_MODE_DISABLED
    case MAVLINK_MSG_ID_HIL_STATE:          // MAV ID: 90
    {
        mavlink_hil_state_t packet;
        mavlink_msg_hil_state_decode(msg, &packet);

        // set gps hil sensor
        Location loc;
        loc.lat = packet.lat;
        loc.lng = packet.lon;
        loc.alt = packet.alt/10;
        Vector3f vel(packet.vx, packet.vy, packet.vz);
        vel *= 0.01f;

        gps.setHIL(0, AP_GPS::GPS_OK_FIX_3D,
                   packet.time_usec/1000,
                   loc, vel, 10, 0, true);

        // rad/sec
        Vector3f gyros;
        gyros.x = packet.rollspeed;
        gyros.y = packet.pitchspeed;
        gyros.z = packet.yawspeed;

        // m/s/s
        Vector3f accels;
        accels.x = packet.xacc * (GRAVITY_MSS/1000.0f);
        accels.y = packet.yacc * (GRAVITY_MSS/1000.0f);
        accels.z = packet.zacc * (GRAVITY_MSS/1000.0f);

        ins.set_gyro(0, gyros);

        ins.set_accel(0, accels);

        copter.barometer.setHIL(packet.alt*0.001f);
        copter.compass.setHIL(0, packet.roll, packet.pitch, packet.yaw);
        copter.compass.setHIL(1, packet.roll, packet.pitch, packet.yaw);

        break;
    }
#endif //  HIL_MODE != HIL_MODE_DISABLED

    case MAVLINK_MSG_ID_RADIO:
    case MAVLINK_MSG_ID_RADIO_STATUS:       // MAV ID: 109
    {
        handle_radio_status(msg, copter.DataFlash, copter.should_log(MASK_LOG_PM));
        break;
    }

    case MAVLINK_MSG_ID_LOG_REQUEST_DATA:
    case MAVLINK_MSG_ID_LOG_ERASE:
        copter.in_log_download = true;
        /* no break */
    case MAVLINK_MSG_ID_LOG_REQUEST_LIST:
        if (!copter.in_mavlink_delay && !copter.motors.armed()) {
            handle_log_message(msg, copter.DataFlash);
        }
        break;
    case MAVLINK_MSG_ID_LOG_REQUEST_END:
        copter.in_log_download = false;
        if (!copter.in_mavlink_delay && !copter.motors.armed()) {
            handle_log_message(msg, copter.DataFlash);
        }
        break;

#if HAL_CPU_CLASS > HAL_CPU_CLASS_16
    case MAVLINK_MSG_ID_SERIAL_CONTROL:
        handle_serial_control(msg, copter.gps);
        break;

    case MAVLINK_MSG_ID_GPS_INJECT_DATA:
        handle_gps_inject(msg, copter.gps);
        result = MAV_RESULT_ACCEPTED;
        break;

#endif

#if PRECISION_LANDING == ENABLED
        case MAVLINK_MSG_ID_LANDING_TARGET:
            // configure or release parachute
            result = MAV_RESULT_ACCEPTED;
            copter.precland.handle_msg(msg);
#endif

#if CAMERA == ENABLED
    //deprecated.  Use MAV_CMD_DO_DIGICAM_CONFIGURE
    case MAVLINK_MSG_ID_DIGICAM_CONFIGURE:      // MAV ID: 202
        break;

    //deprecated.  Use MAV_CMD_DO_DIGICAM_CONTROL
    case MAVLINK_MSG_ID_DIGICAM_CONTROL:
        copter.camera.control_msg(msg);
        copter.log_picture();
        break;
#endif // CAMERA == ENABLED

#if MOUNT == ENABLED
    //deprecated. Use MAV_CMD_DO_MOUNT_CONFIGURE
    case MAVLINK_MSG_ID_MOUNT_CONFIGURE:        // MAV ID: 204
        copter.camera_mount.configure_msg(msg);
        break;
    //deprecated. Use MAV_CMD_DO_MOUNT_CONTROL
    case MAVLINK_MSG_ID_MOUNT_CONTROL:
        copter.camera_mount.control_msg(msg);
        break;
#endif // MOUNT == ENABLED

    case MAVLINK_MSG_ID_TERRAIN_DATA:
    case MAVLINK_MSG_ID_TERRAIN_CHECK:
#if AP_TERRAIN_AVAILABLE
        copter.terrain.handle_data(chan, msg);
#endif
        break;

#if AC_RALLY == ENABLED
    // receive a rally point from GCS and store in EEPROM
    case MAVLINK_MSG_ID_RALLY_POINT: {
        mavlink_rally_point_t packet;
        mavlink_msg_rally_point_decode(msg, &packet);

        if (packet.idx >= copter.rally.get_rally_total() ||
            packet.idx >= copter.rally.get_rally_max()) {
            send_text_P(MAV_SEVERITY_WARNING,PSTR("bad rally point message ID"));
            break;
        }

        if (packet.count != copter.rally.get_rally_total()) {
            send_text_P(MAV_SEVERITY_WARNING,PSTR("bad rally point message count"));
            break;
        }

        RallyLocation rally_point;
        rally_point.lat = packet.lat;
        rally_point.lng = packet.lng;
        rally_point.alt = packet.alt;
        rally_point.break_alt = packet.break_alt;
        rally_point.land_dir = packet.land_dir;
        rally_point.flags = packet.flags;

        if (!copter.rally.set_rally_point_with_index(packet.idx, rally_point)) {
            send_text_P(MAV_SEVERITY_CRITICAL, PSTR("error setting rally point"));
        }

        break;
    }

    //send a rally point to the GCS
    case MAVLINK_MSG_ID_RALLY_FETCH_POINT: {
        //send_text_P(MAV_SEVERITY_CRITICAL, PSTR("## getting rally point in GCS_Mavlink.cpp 1")); // #### TEMP

        mavlink_rally_fetch_point_t packet;
        mavlink_msg_rally_fetch_point_decode(msg, &packet);

        //send_text_P(MAV_SEVERITY_CRITICAL, PSTR("## getting rally point in GCS_Mavlink.cpp 2")); // #### TEMP

        if (packet.idx > copter.rally.get_rally_total()) {
            send_text_P(MAV_SEVERITY_WARNING, PSTR("bad rally point index"));
            break;
        }

        //send_text_P(MAV_SEVERITY_CRITICAL, PSTR("## getting rally point in GCS_Mavlink.cpp 3")); // #### TEMP

        RallyLocation rally_point;
        if (!copter.rally.get_rally_point_with_index(packet.idx, rally_point)) {
           send_text_P(MAV_SEVERITY_WARNING, PSTR("failed to set rally point"));
           break;
        }

        //send_text_P(MAV_SEVERITY_CRITICAL, PSTR("## getting rally point in GCS_Mavlink.cpp 4")); // #### TEMP

        mavlink_msg_rally_point_send_buf(msg,
                                         chan, msg->sysid, msg->compid, packet.idx,
                                         copter.rally.get_rally_total(), rally_point.lat, rally_point.lng,
                                         rally_point.alt, rally_point.break_alt, rally_point.land_dir,
                                         rally_point.flags);

        //send_text_P(MAV_SEVERITY_CRITICAL, PSTR("## getting rally point in GCS_Mavlink.cpp 5")); // #### TEMP

        break;
    }
#endif // AC_RALLY == ENABLED

    case MAVLINK_MSG_ID_AUTOPILOT_VERSION_REQUEST:
        copter.gcs[chan-MAVLINK_COMM_0].send_autopilot_version(FIRMWARE_VERSION);
        break;

    case MAVLINK_MSG_ID_LED_CONTROL:
        // send message to Notify
        AP_Notify::handle_led_control(msg);
        break;

    }     // end switch
} // end handle mavlink


/*
 *  a delay() callback that processes MAVLink packets. We set this as the
 *  callback in long running library initialisation routines to allow
 *  MAVLink to process packets while waiting for the initialisation to
 *  complete
 */
void Copter::mavlink_delay_cb()
{
    static uint32_t last_1hz, last_50hz, last_5s;
    if (!gcs[0].initialised || in_mavlink_delay) return;

    in_mavlink_delay = true;

    uint32_t tnow = millis();
    if (tnow - last_1hz > 1000) {
        last_1hz = tnow;
        gcs_send_heartbeat();
        gcs_send_message(MSG_EXTENDED_STATUS1);
    }
    if (tnow - last_50hz > 20) {
        last_50hz = tnow;
        gcs_check_input();
        gcs_data_stream_send();
        gcs_send_deferred();
        notify.update();
    }
    if (tnow - last_5s > 5000) {
        last_5s = tnow;
        gcs_send_text_P(MAV_SEVERITY_WARNING, PSTR("Initialising APM..."));
    }
    check_usb_mux();

    in_mavlink_delay = false;
}

/*
 *  send a message on both GCS links
 */
void Copter::gcs_send_message(enum ap_message id)
{
    for (uint8_t i=0; i<num_gcs; i++) {
        if (gcs[i].initialised) {
            gcs[i].send_message(id);
        }
    }
}

/*
 *  send a mission item reached message and load the index before the send attempt in case it may get delayed
 */
void Copter::gcs_send_mission_item_reached_message(uint16_t mission_index)
{
    for (uint8_t i=0; i<num_gcs; i++) {
        if (gcs[i].initialised) {
            gcs[i].mission_item_reached_index = mission_index;
            gcs[i].send_message(MSG_MISSION_ITEM_REACHED);
        }
    }
}

/*
 *  send data streams in the given rate range on both links
 */
void Copter::gcs_data_stream_send(void)
{
    for (uint8_t i=0; i<num_gcs; i++) {
        if (gcs[i].initialised) {
            gcs[i].data_stream_send();
        }
    }
}

/*
 *  look for incoming commands on the GCS links
 */
void Copter::gcs_check_input(void)
{
    for (uint8_t i=0; i<num_gcs; i++) {
        if (gcs[i].initialised) {
#if CLI_ENABLED == ENABLED
            gcs[i].update(g.cli_enabled==1?FUNCTOR_BIND_MEMBER(&Copter::run_cli, void, AP_HAL::UARTDriver *):NULL);
#else
            gcs[i].update(NULL);
#endif
        }
    }
}

void Copter::gcs_send_text_P(MAV_SEVERITY severity, const prog_char_t *str)
{
    for (uint8_t i=0; i<num_gcs; i++) {
        if (gcs[i].initialised) {
            gcs[i].send_text_P(severity, str);
        }
    }
}

/*
 *  send a low priority formatted message to the GCS
 *  only one fits in the queue, so if you send more than one before the
 *  last one gets into the serial buffer then the old one will be lost
 */
void Copter::gcs_send_text_fmt(const prog_char_t *fmt, ...)
{
    va_list arg_list;
    gcs[0].pending_status.severity = (uint8_t)MAV_SEVERITY_WARNING;
    va_start(arg_list, fmt);
    hal.util->vsnprintf_P((char *)gcs[0].pending_status.text,
            sizeof(gcs[0].pending_status.text), fmt, arg_list);
    va_end(arg_list);
    gcs[0].send_message(MSG_STATUSTEXT);
    for (uint8_t i=1; i<num_gcs; i++) {
        if (gcs[i].initialised) {
            gcs[i].pending_status = gcs[0].pending_status;
            gcs[i].send_message(MSG_STATUSTEXT);
        }
    }
}