0 Replies Latest reply on Nov 20, 2017 7:06 PM by cesar villalon

    I need help printing in a GX420t

    cesar villalon

      Hi I done a android app and I need to print recieps, I am connection the printer via USB to the android tablet an sending a basic message


      String tmpHeader = "^XA"+ "^FO50,50^ADN,36,20^FDxxxxxxxxxxx^FS"+ "^XZ";


        arregloBytes = tmpHeader.getBytes();




         public void startPrinting(final UsbDevice printerDevice)



         Handler handler = new Handler();

         handler.post(new Runnable()


         UsbDeviceConnection conn;

         UsbInterface usbInterface;

         //@RequiresApi(api = Build.VERSION_CODES.N)


         public void run()




         for (int i = 0; i < printerDevice.getInterfaceCount(); i++)


        usbInterface = printerDevice.getInterface(i);


         UsbEndpoint endPoint = usbInterface.getEndpoint(0);

        conn = mUsbManager.openDevice(mDevice);

         conn.claimInterface(usbInterface, true);

         //conn.bulkTransfer(endPoint, arregloLogo, arregloLogo.length, 0);

         conn.bulkTransfer(endPoint, arregloBytes, arregloBytes.length, 0);


        mPromise = null;




         catch (Exception e)



        mPromise = null;

         Log.e("Exception", "Unable to transfer bulk data");







      the response is successful but it doesn't print anything.


      I use the same code from printing in other printer and it works perfectly

      thank you for your help