Android Question Send hex bytes to TCP

Erel

B4X founder

Staff member

Licensed User

Longtime User

• Mar 18, 2024

• #2

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:

B4X:

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.

 

Upvote 0

S

Sergey_e

Member

• Mar 18, 2024

• #3

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

 

Upvote 0

Erel

B4X founder

Staff member

Licensed User

Longtime User

• Mar 18, 2024

• #4

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.

 

Upvote 0

S

Sergey_e

Member

• Mar 18, 2024

• #5

Thank you very much for your help!

 

Upvote 0

S

Sergey_e

Member

• Mar 18, 2024

• #6

And how to get an answer from the device?

 

Upvote 0

DonManfred

Expert

Licensed User

Longtime User

• Mar 18, 2024

• #7

Sergey_e said:

And how to get an answer from the device?

Click to expand...

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

B4X:

Sub AStream_NewData (Buffer() As Byte)
End Sub

For any new Question you should create a new thread.

 

Upvote 0