无法从微控制器接收UDP数据包

Question

我目前正在通过以太网工作在UDP通信PC <→ARM LM3S6965（Luminary）上。在PC上有一个模拟UDP服务器/客户端的VB.net应用程序。

当数据包从PC发送到ARM LM3S6965时，数据包接收没有错误，但是当ARM LM3S6965将UDP数据包发送回PC时，数据包在某处丢失（应用程序没有收到它）。

奇怪的是，WireShark捕获到PC的这些数据包，看起来它们是有效的。

在Windows中关闭防火墙并没有帮助。我知道这个主题可能对这个论坛是错误的，但任何人都可以解释为什么WireShark捕获这些数据包，但我的应用程序没有？ ARM LM3S6965（192.168.0.100），PC（192.168.0.116），发送和接收端口号为3040，并且我正在从ARM LM3S6965微控制器接收的VB.Net应用程序发送广播消息。

下面是VB.net代码：

Public Const mnPort As Int16 = 3040        'Port number to send/recieve data on 
Public Const msBroadcastAddress As String = "255.255.255.255" 'Sends data to all LOCAL listening clients, to send data over WAN you'll need to enter a public (external) IP address of the other client 
Public udpReceivingClient As UdpClient       'Client for handling incoming data 
Public udpSendingClient As UdpClient       'Client for sending data 
Public receivingThread As Thread        'Create a separate thread to listen for incoming data, helps to prevent the form from freezing up 
Public mbiClosing As Boolean = False       'Used to close clients if form is closing 


Public Sub InitializeSender() 
    udpSendingClient = New UdpClient(msBroadcastAddress, mnPort) 
    udpSendingClient.EnableBroadcast = True 
End Sub 

Public Sub InitializeReceiver() 
    udpReceivingClient = New UdpClient(mnPort) 
    'Dim start As ThreadStart = New ThreadStart(AddressOf MT_Receiver) 
    'receivingThread = New Thread(start) 
    'receivingThread.IsBackground = True 
    'receivingThread.Start() 
End Sub 

Public Sub MT_Send_UDP(ByVal lbTxBuffer() As Byte) 

    Try 
     udpSendingClient.Send(lbTxBuffer, lbTxBuffer.Length) 
    Catch ex As Exception 
     MsgBox(ex.ToString) 
    End Try 

    Try 
     udpReceivingClient.BeginReceive(AddressOf MT_RX_Callback, Nothing) 
    Catch ex As Exception 
     MsgBox(ex.ToString) 
    End Try 
End Sub 

Public Sub MT_RX_Callback(ByVal IR As IAsyncResult) 
    Dim endPoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 3040) 
    Dim lbData() As Byte 
    Dim llRet As UInt16 
    If mbiClosing = False Then 
     llRet = udpReceivingClient.Available 
     lbData = udpReceivingClient.EndReceive(IR, endPoint) 

     If llRet > 0 Then 
      MT_Validate_Msg(lbData) 
     End If 

     udpReceivingClient.BeginReceive(AddressOf MT_RX_Callback, Nothing) 
    End If 
End Sub 

Private Sub frmSearchUDP_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing 
    mbiClosing = True 

    udpReceivingClient.Close() 
    udpSendingClient.Close() 
    frmMain.Timer.Enabled = True 
End Sub 

Private Sub frmSearchUDP_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
    InitializeSender() 
    InitializeReceiver() 

End Sub 

Answer 1

更多评论，但它太长时间......

No196：42.430628
从192.168.0.168 - > 255.255。 255.255（从您的PC到您的硬件）
UDP ...源端口：63162（63162）
目标端口：番茄温泉（3040）

这看起来不错，它显然工作，因为您的硬件发送响应。

No197：42.431017
从192.168.0.100 - > 255.255.255.255（从硬件到您的PC）
源端口：番茄弹簧（3040）
目标端口：63162（63162）

为什么你的PC应该收到这个数据包？
目的端口是63162，但你听端口3040