Failed to receive data over usb using Usbserial example

Question

I am using following UsbSerial example from below link https://github.com/felHR85/SerialPortExample. I want receive data from over usb from the device shown in the photo.

Device is basically a counter machine which is sending counter data over serial port.

I am able to connect device and open port from it but unable to read data stream from it. Below is the code used. code is not giving any error

Mainactivity class

public class MainActivity extends AppCompatActivity {

    /*
     * Notifications from UsbService will be received here.
     */
    private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            switch (intent.getAction()) {
                case UsbService.ACTION_USB_PERMISSION_GRANTED: // USB PERMISSION GRANTED
                    Toast.makeText(context, "USB Ready", Toast.LENGTH_SHORT).show();
                    break;
                case UsbService.ACTION_USB_PERMISSION_NOT_GRANTED: // USB PERMISSION NOT GRANTED
                    Toast.makeText(context, "USB Permission not granted", Toast.LENGTH_SHORT).show();
                    break;
                case UsbService.ACTION_NO_USB: // NO USB CONNECTED
                    Toast.makeText(context, "No USB connected", Toast.LENGTH_SHORT).show();
                    break;
                case UsbService.ACTION_USB_DISCONNECTED: // USB DISCONNECTED
                    Toast.makeText(context, "USB disconnected", Toast.LENGTH_SHORT).show();
                    break;
                case UsbService.ACTION_USB_NOT_SUPPORTED: // USB NOT SUPPORTED
                    Toast.makeText(context, "USB device not supported", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    };
    private UsbService usbService;
    private TextView display;
    private EditText editText;
    private MyHandler mHandler;
    private final ServiceConnection usbConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName arg0, IBinder arg1) {
            usbService = ((UsbService.UsbBinder) arg1).getService();
            usbService.setHandler(mHandler);
        }

        @Override
        public void onServiceDisconnected(ComponentName arg0) {
            usbService = null;
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mHandler = new MyHandler(this);
        display = (TextView) findViewById(R.id.textView1);
        editText = (EditText) findViewById(R.id.editText1);
        Button sendButton = (Button) findViewById(R.id.buttonSend);
        sendButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!editText.getText().toString().equals("")) {
                    String data = editText.getText().toString();
                    if (usbService != null) { // if UsbService was correctly binded, Send data
                        display.append(data);
                        usbService.write(data.getBytes());
                    }
                }
            }
        });
    }

    @Override
    public void onResume() {
        super.onResume();
        setFilters();  // Start listening notifications from UsbService
        startService(UsbService.class, usbConnection, null); // Start UsbService(if it was not started before) and Bind it
    }

    @Override
    public void onPause() {
        super.onPause();
        unregisterReceiver(mUsbReceiver);
        unbindService(usbConnection);
    }

    private void startService(Class<?> service, ServiceConnection serviceConnection, Bundle extras) {
        if (!UsbService.SERVICE_CONNECTED) {
            Intent startService = new Intent(this, service);
            if (extras != null && !extras.isEmpty()) {
                Set<String> keys = extras.keySet();
                for (String key : keys) {
                    String extra = extras.getString(key);
                    startService.putExtra(key, extra);
                }
            }
            startService(startService);
        }
        Intent bindingIntent = new Intent(this, service);
        bindService(bindingIntent, serviceConnection, Context.BIND_AUTO_CREATE);
    }

    private void setFilters() {
        IntentFilter filter = new IntentFilter();
        filter.addAction(UsbService.ACTION_USB_PERMISSION_GRANTED);
        filter.addAction(UsbService.ACTION_NO_USB);
        filter.addAction(UsbService.ACTION_USB_DISCONNECTED);
        filter.addAction(UsbService.ACTION_USB_NOT_SUPPORTED);
        filter.addAction(UsbService.ACTION_USB_PERMISSION_NOT_GRANTED);
        registerReceiver(mUsbReceiver, filter);
    }

    /*
     * This handler will be passed to UsbService. Data received from serial port is displayed through this handler
     */
    private static class MyHandler extends Handler {
        private final WeakReference<MainActivity> mActivity;

        public MyHandler(MainActivity activity) {
            mActivity = new WeakReference<>(activity);
        }

        @Override
        public void handleMessage(Message msg) {
            mActivity.get().display.append("Handle:");
            switch (msg.what) {
                case UsbService.MESSAGE_FROM_SERIAL_PORT:
                    String data = (String) msg.obj;
                    mActivity.get().display.append(data);
                    break;
            }
        }
    }
}

score 0 · Answer 1 · answered Jun 27 '16 at 07:16

I know it's bit late, however just to help others who might come across similar issue, did you find solution to your problem? If not, I cannot see the other java file corresponding to the service (USBService.java) as described in the example referred by you. The same file contains following code snippet which you would like to debug to find out what's going wrong (could be a problem with byte to string conversion or so). Hope this helps.

    /*
 *  Data received from serial port will be received here. Just populate onReceivedData with your code
 *  In this particular example. byte stream is converted to String and send to UI thread to
 *  be treated there.
 */
private UsbSerialInterface.UsbReadCallback mCallback = new UsbSerialInterface.UsbReadCallback()
{
    @Override
    public void onReceivedData(byte[] arg0)
    {
        try
        {
            String data = new String(arg0, "UTF-8");
            if(mHandler != null)
                mHandler.obtainMessage(MESSAGE_FROM_SERIAL_PORT,data).sendToTarget();
        } catch (UnsupportedEncodingException e)
        {
            e.printStackTrace();
        }
    }
};

Failed to receive data over usb using Usbserial example

1 Answers1