ส่งค่าตัวแปรไปในtext file receipt
[1] mTxtFilename holds the name of the file the user has selected
[2] ensure we are connected
[3] we can also query the printer status asyncronously
[4] read the data as is means read it as ByteArrayInputStream
If the binary data is read as InputStream it is converted to unicode. But it has to remain as is and found I had to read it as ByteArrayInputStream to get unconverted data.
[5] open the stream using an asset file
[6] read and write the data in chunks