Android Question UsbSerial and OutputStream

[wroyw]

Hi,

I have a problem with this code :

        If usb.Open( 9600,OptDev.USBidx+1) = usb.USB_DEVICE Then
           Dim os As OutputStream = usb.GetOutputStream
           os.WriteBytes(Array As Byte (0x0f),0,1)

at the WriteByte method it crashes :
java.lang.RuntimeException: This method is not supported.
at anywheresoftware.b4a.objects.UsbSerial$2.write(UsbSerial.java:258)
at java.iutputStream.write(OutputStream.java:106)
at anywheresoftware.b4a.objects.streams.File$OutputStreamWrapper.WriteBytes(File.java:455)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:755)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:345)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:167)
at anywheresoftware.b4a.debug.Debug.delegate(Debug.java:259)
at b4a.example.main._checkdevices(main.java:1000)
at b4a.example.main._activity_create(main.java:938)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.example.main.afterFirstLayout(main.java:102)
at b4a.example.main.access$000(main.java:17)
at b4a.example.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7229)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)


What is wrong ?

 

[Erel]

As the first sentence in the library documentation says: https://www.b4x.com/android/forum/threads/usbserial-library-2-0-supports-more-devices.28176/ you need to use AsyncStreams with UsbSerial.