device is closed in native_control_request ISSUE

[jparedesj]

Hello,

I don't know if this is an issue of the UsbSeria libraryl or my implementation is bad.

Anyway this UsbSerial it's great!

I had the following code in a click event. It works fine one or two times, then I get "device is closed in native_control_request".

It fails in this piece of code with the following error because "position" it's still "-1" after "wait()".

11-03 20:58:29.836: E/AndroidRuntime(7937): FATAL EXCEPTION: Thread-445 11-03 20:58:29.836: E/AndroidRuntime(7937): java.lang.IllegalArgumentException 11-03 20:58:29.836: E/AndroidRuntime(7937): at java.util.Arrays.copyOfRange(Arrays.java:2691) 11-03 20:58:29.836: E/AndroidRuntime(7937): at com.felhr.usbserial.SerialBuffer$SynchronizedBuffer.get(SerialBuffer.java:152) 11-03 20:58:29.836: E/AndroidRuntime(7937): at com.felhr.usbserial.SerialBuffer.getWriteBuffer(SerialBuffer.java:83) 11-03 20:58:29.836: E/AndroidRuntime(7937): at com.felhr.usbserial.UsbSerialDevice$WriteThread.run(UsbSerialDevice.java:218)

public synchronized byte[] get() { if(position == -1) { try { wait(); } catch (InterruptedException e) { e.printStackTrace(); } }

        byte[] dst =  Arrays.copyOfRange(buffer, 0, position);
        if(debugging)
            UsbSerialDebugger.printLogGet(dst, true);
        position = -1;
        return dst;
    }

Here is what I have in my onclick event....

It is a 4.2.2 Android (Rikomagic MK802IV)

            UsbManager lclMan=(UsbManager) getSystemService(Context.USB_SERVICE);

            UsbDeviceConnection lclusbConnection=lclMan.openDevice(dev);

            PL2303SerialDevice us=new PL2303SerialDevice(dev, lclusbConnection);
            us.debug(true);
            Log.d("SPOOL","TENGO EL OBJETO");
            us.open();

            String b="HOLA MUNDO\nHOLA MUNDO\nHOLA MUNDO\nHOLA MUNDO \n";

            us.setBaudRate(57600);

            us.setDataBits(p.getBaudRate());

            us.setParity(p.getParity());

            us.setStopBits(p.getStopBits());

            us.read(mCallback);

            us.write(b.getBytes());

            us.close();

[felHR85]

Hello, I will check this further but, in the meantime, you could extract of the onClick event near all of that. Ideally your onClick button should be like this:

public void onClick(View arg0) { us.write(b.getBytes()); } });

I have an example in production which is very similar and the only thing which I am not doing everytime a button is pressed is UsbManager lclMan=(UsbManager) getSystemService(Context.USB_SERVICE);

Please, tell me if this is working for you.

[felHR85]

This looks like some internal android stuff http://stackoverflow.com/questions/15446413/usbconnection-bulktransfer-returns-1-what-does-it-mean

It looks like a good thing to avoid open and close devices very often.

[jparedesj]

Thanks for your answer.

I will try to modify my logic today to keep the connection always open until the activity stops.

I'll let you know.

[jparedesj]

It works perfectly after the change of logic.

Thanks for the tip. I think it's an Android issue...

Regards!

[felHR85]

I close the issue. I added further information about UsbSerial here http://felhr85.net/2014/11/11/usbserial-a-serial-port-driver-library-for-android-v2-0/

Regards!