I've decided to port a QR code library onto the TI-84+CE, and found https://github.com/ricmoo/QRCode
, which is portable and optimized for low-power devices.
To compile that library for the calculator (with Zilog's ANSI C compiler included), I had to rewrite some of the code to compile under ANSI C, as the compiler was complaining.
Anyway, when you run the demo program (DEMO.8xp, see below), it's going to take about a minute to process and then you'll get a QR code with the sample message displayed on the calculator screen.
Press any key to exit the demo program.