I need an array of about 300 small LED's, each about 3-5 mm wide. The hard part is this: I need to be able to switch on/off one of all these (i.e. only one led is lit at any time). The number of cables required should be about 2*sqrt(300), right?
How do I build such a controller? Can I buy it somewhere? Where do I find the LED's?
Any help would be appreciated.