Wait, what ? Two-factor authentication codes on a TI-89 ? ? ?
key_parm = base32_decode(key, x, 16);
https://github.com/arcanericky/ga-cmd/blob/master/src/codegen.c#L15
Really? There are 32 characters in a totp secret, yet you only decode 16? wtf?
Well, thankfully, I figured out the problem ...