Re: [wsjt-devel] WSJT-X 2.0.1 QSO ADIF transmission on the UDP port. Defect or Design?

[Bill S. <g4...@cl...>]

On 27/03/2019 03:12, Ed Stokes wrote:
> // kGroupAddress = 127.0.0.1
> // kOutPort = 61880
>
> Dim d As new Datagram
> Dim clearMessage As String
>
> clearMessage = ChrB(&hAD) + ChrB(&hBC) + ChrB(&hCB) + ChrB(&hDA)
> clearMessage = clearMessage + ChrB(&h0) + ChrB(&h0) + ChrB(&h0) + 
> ChrB(&h2)
> clearMessage = clearMessage + ChrB(&h0) + ChrB(&h0) + ChrB(&h0) + 
> ChrB(&h3)
> clearMessage = clearMessage + ChrB(&h2)  //  + ChrB(&h0)
>
> d.Address = kGroupAddress
> d.Port = kOutPort
> d.Data = clearMessage
>
> UdPSocket1.Write( d )
>
> This did not produce any effect.  So then, I thought perhaps I needed 
> another UDP socket as #1 was connected to port 2237.
>
Hi Ed,

there's no problem with using the same socket for sending and receiving, 
that's pretty standard with UDP. You have a few issues remaining. It 
looks like you are hard coding the send address and port, don't do that 
as the port will change and the address might too. You must use the 
sender address and port as given to you from a previous datagram 
receive. The next issue is that you do not have the Clear message fields 
correct, there is an 'id' field after the message type field. It is a 
UTF-8 string field which can be empty or null as currently WSJT-X 
doesn't do anything with it. Either put your application name in, send 
an empty string 9an empty string is a count sub-field containing the 
value zero unsigned 32-bit), or send a null string (count as &hfffffffff).

You are probably not using the right tools for the job, Xojo has some 
types that make network message parsing and building really easy. Here 
is how I would read a message:

Const magic As UInt32 = &hadbccbda
Dim dg As Datagram = WSJTXSocket.Read
Dim is As New BinaryStream (dg.Data)
If is.ReadUInt32 <> magic Then Return
Dim schema As UInt32 = is.ReadUInt32
Dim msg_type As Uint32 = is.ReadUInt32
Dim length as UInt32 = is.ReadUInt32
Dim id As String
if length > 0 And length < &hffffffff Then id = is.Read (length, Encodings.UTF8)

Select Case msg_type
Case 0 ' Heartbeat

Case 2 ' Decode
   Dim is_new As Boolean = is.ReadBoolean
   Dim ms As UInt32 = is.ReadUInt32 ' ms since midnight
   Dim snr As UInt32 = is.ReadInt32
   Dim dt As Double = is.ReadDouble
   Dim df As UInt32 = is.readUInt32
   Dim mode As String = is.Read (is.ReadUInt32, Encodings.UTF8)
   Dim message As String = is.Read (is.ReadUInt32, Encodings.UTF8)
   Dim low_confidence As Boolean = is.ReadBoolean
   Dim off_air As Boolean = is.ReadBoolean

Case 6 ' Close
End Select

The same applies to building outgoing messages:

Dim mb As New MemoryBlock (0)
Dim os As New BinaryStream (mb)
os.LittleEndian = False
os.WriteUInt32 (magic)
os.WriteUInt32 (2)
os.WriteUInt32 (3) ' Clear
os.WriteUInt32 (&hffffffff) ' Null id string
os.WriteUInt8 (0) ' Clear Band Activity window
Dim msg As Datagram
msg.Address = dg.Address
msg.Port = dg.Port
msg.Data = mb
WSJTXSocket.Write (msg)

73
Bill
G4WJS.