the electronics of the display aren't a problem. digital matrix with diodes, PIC, it's relatively simple to do. the problem is having a foolproof method of detecting the position of the stick. mine, like i say has very little lateral movement and things like reed switches, photo transistors, hall effect sensors, etc will likely suffer from some mis-readings at some stage. especially as the stick also has a certain amount of slop to it and moves around significantly while driving. the best solution i've found so far is some arrangement to detect top, left, bottom and right positions of the stick and using a PIC to "decode" the switch combinations (ie, top and left = 1st, bottom and left = 2nd, top only = 3rd, etc). my current plan of attack is to do this with a simple 4 microswitch set up or something similar.