Ti-84 and arduino

Hey,

I have an arduino Uno R3, and a MEGA 2560

That article actually looks perfect!
I guess it came out recently because I have been researching this for a while.

Because I'm not a subscriber to that magazine, if you are, can you let me know if they are using the 2.5mm link cable or the USB?
Doesn't specify in the download files.

Thanks