Discussion in 'Android Questions' started by Sganga61, Jul 17, 2017.

  1. Sganga61

    Sganga61 Member Licensed User

    I need to add code to my application to use the embedded serial port (RS232) of my industrial tablet using B4A.
    Following some examples found on the forum I add this simple code:

    (in the global)
    Dim SerialPort As AsyncStreams

    (in start activity)
    fo = File.OpenOutput("","/dev/ttyS0", False) '********
    fi = File.OpenInput("","/dev/ttyS0")

    (then in the code)
    Sub astreams_NewData (Buffer() As Byte)
    Log(BytesToString(Buffer, 0, Buffer.Length, "UTF8"))
    End Sub

    Sub STESTn_Click
    File.WriteString("/dev/ttyS0", "","serial comm test" & CRLF)
    End Sub


    In debug mode reaching the line with '****** I get the following error and program closed:

    error occured on line ...... (dev/ttyso: open failed: EACCES (permission denied)

    PS: the file ttyso already exist in the system dev/ folder

    Who can help me?
  2. Erel

    Erel Administrator Staff Member Licensed User

    Please use [code]code here...[/code] tags when posting code.

    Did you receive any documentation about this feature from the device manufacturer?
  3. Peter Simpson

    Peter Simpson Expert Licensed User

    What's the make and model of your industrial tablet...
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