I'll try to get around and fix the fps startup issue. I just haven't found the error in the code yet. I think it could be solved by checking the shutter state one more time.
About the characters, this was something I looked into earlier. The problem is that ISO-8859-something or UTF-8 is usually the encoding used for qr codes, but there is no default encoding in the specification, so everything, including UTF-8, might be used. In other words, if there is no information about the character encoding used by the qr encoder, there is no way to know what it is. I suggest we go with assuming UTF-8, as it is most universal, unless there are any encoding hints in the code.