MissionPlanner.MAVLinkInterface.OpenBg C# (CSharp) Method

        private void OpenBg(object PRsender, bool getparams, ProgressWorkerEventArgs progressWorkerEventArgs)
        {
            frmProgressReporter.UpdateProgressAndStatus(-1, Strings.MavlinkConnecting);

            giveComport = true;

            if (BaseStream is SerialPort)
            {
                // allow settings to settle - previous dtr 
                System.Threading.Thread.Sleep(1000);
            }

            Terrain = new TerrainFollow(this);

            bool hbseen = false;

            try
            {
                BaseStream.ReadBufferSize = 16*1024;

                lock (objlock) // so we dont have random traffic
                {
                    log.Info("Open port with " + BaseStream.PortName + " " + BaseStream.BaudRate);

                    BaseStream.Open();

                    BaseStream.DiscardInBuffer();

                    // other boards seem to have issues if there is no delay? posible bootloader timeout issue
                    Thread.Sleep(1000);
                }

                MAVLinkMessage buffer = MAVLinkMessage.Invalid;
                MAVLinkMessage buffer1 = MAVLinkMessage.Invalid;

                DateTime start = DateTime.Now;
                DateTime deadline = start.AddSeconds(CONNECT_TIMEOUT_SECONDS);

                var countDown = new System.Timers.Timer {Interval = 1000, AutoReset = false};
                countDown.Elapsed += (sender, e) =>
                {
                    int secondsRemaining = (deadline - e.SignalTime).Seconds;
                    frmProgressReporter.UpdateProgressAndStatus(-1, string.Format(Strings.Trying, secondsRemaining));
                    if (secondsRemaining > 0) countDown.Start();
                };
                countDown.Start();

                // px4 native
                BaseStream.WriteLine("sh /etc/init.d/rc.usb");

                int count = 0;

                while (true)
                {
                    if (progressWorkerEventArgs.CancelRequested)
                    {
                        progressWorkerEventArgs.CancelAcknowledged = true;
                        countDown.Stop();
                        if (BaseStream.IsOpen)
                            BaseStream.Close();
                        giveComport = false;
                        return;
                    }

                    log.Info(DateTime.Now.Millisecond + " Start connect loop ");

                    if (DateTime.Now > deadline)
                    {
                        //if (Progress != null)
                        //    Progress(-1, "No Heartbeat Packets");
                        countDown.Stop();
                        this.Close();

                        if (hbseen)
                        {
                            progressWorkerEventArgs.ErrorMessage = Strings.Only1Hb;
                            throw new Exception(Strings.Only1HbD);
                        }
                        else
                        {
                            progressWorkerEventArgs.ErrorMessage = "No Heartbeat Packets Received";
                            throw new Exception(@"Can not establish a connection\n
Please check the following
1. You have firmware loaded
2. You have the correct serial port selected
3. PX4 - You have the microsd card installed
4. Try a diffrent usb port\n\n" +
                                                "No Mavlink Heartbeat Packets where read from this port - Verify Baud Rate and setup\nMission Planner waits for 2 valid heartbeat packets before connecting");
                        }
                    }

                    System.Threading.Thread.Sleep(1);

                    // can see 2 heartbeat packets at any time, and will connect - was one after the other

                    if (buffer.Length == 0)
                        buffer = getHeartBeat();

                    System.Threading.Thread.Sleep(1);

                    if (buffer1.Length == 0)
                        buffer1 = getHeartBeat();


                    if (buffer.Length > 0 || buffer1.Length > 0)
                        hbseen = true;

                    count++;

                    // 2 hbs that match
                    if (buffer.Length > 5 && buffer1.Length > 5 && buffer.sysid == buffer1.sysid && buffer.compid == buffer1.compid)
                    {
                        mavlink_heartbeat_t hb = buffer.ToStructure<mavlink_heartbeat_t>();

                        if (hb.type != (byte) MAVLink.MAV_TYPE.GCS)
                        {
                            SetupMavConnect(buffer, hb);
                            break;
                        }
                    }

                    // 2 hb's that dont match. more than one sysid here
                    if (buffer.Length > 5 && buffer1.Length > 5 && (buffer.sysid == buffer1.sysid || buffer.compid == buffer1.compid))
                    {
                        mavlink_heartbeat_t hb = buffer.ToStructure<mavlink_heartbeat_t>();

                        if (hb.type != (byte) MAVLink.MAV_TYPE.ANTENNA_TRACKER && hb.type != (byte) MAVLink.MAV_TYPE.GCS)
                        {
                            SetupMavConnect(buffer, hb);
                            break;
                        }

                        hb = buffer1.ToStructure<mavlink_heartbeat_t>();

                        if (hb.type != (byte) MAVLink.MAV_TYPE.ANTENNA_TRACKER && hb.type != (byte) MAVLink.MAV_TYPE.GCS)
                        {
                            SetupMavConnect(buffer1, hb);
                            break;
                        }
                    }
                }

                countDown.Stop();

                getVersion();

                frmProgressReporter.UpdateProgressAndStatus(0,
                    "Getting Params.. (sysid " + MAV.sysid + " compid " + MAV.compid + ") ");

                byte[] temp = ASCIIEncoding.ASCII.GetBytes("Mission Planner " + Application.ProductVersion + "\0");
                Array.Resize(ref temp, 50);
                // 
                generatePacket((byte)MAVLINK_MSG_ID.STATUSTEXT,
                    new mavlink_statustext_t() { severity = (byte)MAV_SEVERITY.INFO, text = temp });
                // mavlink2
                generatePacket((byte) MAVLINK_MSG_ID.STATUSTEXT,
                    new mavlink_statustext_t() {severity = (byte) MAV_SEVERITY.INFO, text = temp}, sysidcurrent,
                    compidcurrent, true, true);

                if (getparams)
                {
                    getParamListBG();
                }

                if (frmProgressReporter.doWorkArgs.CancelAcknowledged == true)
                {
                    giveComport = false;
                    if (BaseStream.IsOpen)
                        BaseStream.Close();
                    return;
                }
            }
            catch (Exception e)
            {
                try
                {
                    BaseStream.Close();
                }
                catch
                {
                }
                giveComport = false;
                if (string.IsNullOrEmpty(progressWorkerEventArgs.ErrorMessage))
                    progressWorkerEventArgs.ErrorMessage = Strings.ConnectFailed;
                log.Error(e);
                throw;
            }
            //frmProgressReporter.Close();
            giveComport = false;
            frmProgressReporter.UpdateProgressAndStatus(100, Strings.Done);
            log.Info("Done open " + MAV.sysid + " " + MAV.compid);
            MAV.packetslost = 0;
            MAV.synclost = 0;
        }