Hey guys
I was wondering if it would be possible to controll the Arduino with a TI Graphing Calculator, and specifically the TI89 Titanium because it has a USB port built right in. I know it seems redundant to plug a calculator into this board and run code off of it, on something that is fully capable of being independant, but its for a robot and since the Arduino lacks an LCD screen, I thought it would be neat to use a TI calculator with it ( almost every single person that went through high school in that past decade has one) to output sensor info and use the extra memory for differnt programs if your caught somewhere you dont have a computer to quickly change a program (quite common in robotics since things tend to need tweaking ever so often). Anyway, just let me know your thoughts on that and if it is possible, how would be nice as well. Thanks in advance- Brandon
Well ... this has already been done with other microcontrollers, so it might be possible theorically, but concerning practice ...
Here are some informations I found looking on the internet for the same reasons (I actually have 2 TI-89, one has its screen broken):
Welcome to the TiLP web site : provides a Link Protocol Guide for all TIs, which you are going to realize soon it is not so simple ...
Good luck, keep posting on this forum if you can make anything 
By the way, there should be easier ways to interface Arduino with an LCD screen !!!