Inspired by i've made a little tool for simply QR-Code creation with all required stuff in the au3-file (dll included as binary string, because that, the au3 has 447kB and can not attached directly).
By testing on my system the max. possible count of chars to encode are: $__QR_MAX_LEN = 3049. But on other systems it was round 2000 chars.
Also on another computer the creation of QR-Code fails generally. But ist was the same system that i have (Win 7, 64 bit). I do not know the reason for this