byte [] buf = new byte[1];
buf[1]= 0x01;
usbResult = usbDeviceConnection.controlTransfer(
      0x21,   // bmRequestType
      0x01,   // bRequest
      0x0100, // wValue
      0x0000, // wIndex)
      buf,    // Mute: 0x01  (Data)
      1,      //wLength
      0);     //timeout