Android Question Send hex bytes to TCP

[Sergey_e]

Hi everyone!
I'm new to B4A. Programming in VB.net
I want to make a project for a mobile phone to send and receive data over TCP.
I used an example of TestSockets. But my controller (USR K7) does not accept the data I send to HEX.
For example, in vb.net I have a data packet: FF A1 C3 01 10 FD. But in this example, the same packet is not formed. I ask you to help me find a mistake.

 

[Erel]

Start with this example: [B4X] [B4XPages] Network + AsyncStreams + B4XSerializator
Never implement communication code in activities. Switch to B4XPages.

You are sending the hex as string.
Send the bytes directly:

Dim buffer() As Byte = Array As Byte(0xFF,0xA1,0xC3,0x01,0x10,0xFD)
AStream.Write(buffer)

You are using AsyncStreams in prefix mode. This will only work if the client also implements this protocol.

 

[Sergey_e]

Thank you! It works!
There's another question. How do I substitute data from a text field.
Dim buffer() As Byte = Array As Byte(txt_out.Text)
It doesn't work like that

 

[Erel]

It depends on what you are trying to send. If you want to send the string then call GetBytes to convert it to bytes. If the string itself is in hex format then use ByteConverter.HexToBytes (or BytesFromHex) to convert it to an array of bytes.

 

[Sergey_e]

Thank you very much for your help!

 

[Sergey_e]

And how to get an answer from the device?

 

[DonManfred]

And how to get an answer from the device?

See the example Erel linked.
Incoming data are inside the newdata event

Sub AStream_NewData (Buffer() As Byte)
End Sub

For any new Question you should create a new thread.