This is going to be awfully slow if you have to read data from the SD card all the time. How fast are you expecting to be updating the stepper motors? The 1284 should have enough static ram to allow you to read the whole table into ram on startup.
I haven't thought of that, I'm not sure how your planning on doing it, but the faster the better so I'm all for it. optimally, I would like 4 times a second minimum.
I don't know anything about what your thinking, but I would really like for the user to be able to change the map at any point. so make a function or something to change the map the arduino has. If it takes up to 10 seconds to actually change that map that would be fine. Juts to see, I used excel and made a rough map the size I need, and saved it as a text file. It say "size 3kb, size on disk 4kb" not sure which one we care about. IIRC, the 1284 has 16kb of ram, so that should leave plenty of ram to do other things.
Really interested in what your thinking!!! Thanks
had a really crazy Idea, what if you had a for loop make all the combinations of variables, ie it makes a byte with the name of 25450 and then sets the value to 6, then when you go to retrieve the value, make a string with the data from sensors Y and X.
X = 25
Y = 450
int Val = String(x+y);//this probably isn't the right way, so if anyone know how to correctly do it that would be awesome.