void loop() {

  // Initialize the required buffers
  mavlink_rc_channels_override_t sp;
  mavlink_message_t msg;
  uint8_t buf[MAVLINK_MAX_PACKET_LEN];

  //We have to send the heartbeats to indicate side by side connection
  mav_heartbeat_pack();

  mav_set_mode(current_mode);

  mav_arm_pack(current_arm);

  // ROLL, PITCH, THROTTLE, YAW
  mav_override_rc(current_roll, current_pitch, current_throttle, current_yaw);

  ...
}