B4A Library [class] AsyncStreamsText - Useful when working with streams of text

Is there some advantage of the AsyncStreamsText example compared to using textreader since in both variants only text can be transmitted?

When I compile or invoke the libraries (network and random access) the windows firewall is asking if java shall be blocked or not. I am curious on the reason for internet access when it seems not to be needed...
Regards, positrom2

 

Hi Erel,
thanks for the answers.

I am using textreader in BT and WiFi connections. What happens, is that the code will wait "forever" until text (data numbers) are coming in terminated by CR&LF (or one of those, not sure). Although that is waisting CPU time, it assures that I know that I am subsequently processing the actual data. Consider trying to synchronize the steps of a stepper motor with data read in corresponding to the actual position of the motor. Would that be possible with asyncstreams? If data were fetched as they come in and the data processing would run independently I suspect that synchronization is less than straightforward to achieve.

As you see, I am following the asyncstream posts since I would like to receive the data in binary format (I had some posts here on this issue earlier). So the questions are if my assumptions mentioned here are right - and if not how - how your example could be modified to receive a binary data stream.
Regards, positrom2

 

Erel, I'm getting an error ast not initialized. Any help appreciated...

 

Erel, how would I have to start, to mod this class for bluetooth text comms?

Thanks

 

Also,

Could this be used with USBSerial Comms??

Thanks

Stu

 

It should do as it sits on top of AsyncStreams and doesn't know about anything underneath. Why not just try it?

 

Thank You!

Erel,

Just wanted to thank you for this class buddy! It came handy!!


R

 

Hi Errol, thanks for the AsyncStreamsText Class. When I run the app (your example code), I am getting an error:
asyncstreamstext_write (java line: 140)
java.io.UnsupportedEncodingException:

Not sure how to fix it. :sign0163:

 

Don't worry. I managed to fix the problem... Thanks anyway!

 

What happens when you load a module? Does it show up somewhere that it's loaded?

Ok, on a new tab. Neat.

 

Great work as always, Erel.

 

I'm trying the code listing in the first post (by Erel) substituting a Usb connection for server connection, and the "Private ast As AsyncSteamsText" line in Process Globals is not accepted (red) in B4A. I also downloaded the attached AstreamsText.bas which is a "class" which doesn't appear to be connected to the presented code. What am I doing wrong, as I'm trying to use the posted code to receive text from a ucomputer via a usb connection. The usb connection funtions with the AsyncStreams code, but I have a problem with errors in byte reception, and the data is text anyway.

 

Erel Thanks for the speedy reply and
Yes I added the module.
I then replaced

Code:

Sub Process_Globals
Private ast As AsyncSteamsText
Private server As ServerSocket
End Sub

with

Code:

Sub Process_Globals
Dim ast As AsyncStreamsText
Dim usb As UsbSerial
End Sub

Then I substituted the posted code section

Code:

Sub Activity_Create(FirstTime AsBoolean)
If FirstTime Then
server.Initialize(5555, "server")Log(server.GetMyWifiIP)
server.Listen
EndIf
End Sub
Sub server_NewConnection (Successful As Boolean, NewSocket As Socket)
  If Successful Then
      If ast.IsInitialized Then ast.Close
      ast.Initialize(Me, "ast", NewSocket.InputStream, NewSocket.OutputStream) 'initialize AsyncStreamsText with the socket streams.
  Else
      Log(LastException)
  End If
  server.Listen
End Sub

With this code

Code:

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("1")
   btnClose.Enabled = False
   btnSend.Enabled = False
End Sub

Sub btnOpen_Click
   If usb.UsbPresent = usb.USB_NONE Then
     Log("Msgbox - no device")
     Msgbox("No USB device or accessory detected!", "Error")
     Log("Msgbox - returned")
     Return
   End If
  
   Log("Checking permission")
   If (usb.HasPermission) Then
     'Msgbox(usb.DeviceInfo, "Device Information")
     usb.SetParameters(9600,8,1,0)
     usb.UsbTimeout = 1000
    
     Dim dev As Int
     dev = usb.Open(9600)
     'usb.UsbTimeout=100
    
     If dev <> usb.USB_NONE Then
       Log("Connected successfully!")
       btnOpen.Enabled = False
       btnClose.Enabled = True
       btnSend.Enabled = True
      ast.Initialize(usb.GetInputStream, usb.GetOutputStream, "ast")
      
     Else
       Log("Error opening USB port")
     End If
   Else
     usb.RequestPermission
   End If
  
End Sub

And the code

Code:

ast.Initialize(usb.GetInputStream, usb.GetOutputStream, "ast")

gives a compiler error.