Here's an interesting project 
				from a reader:
				
				
				
				It is basically a 3D arrangement of LEDs driven from a computer. 
				The model above contains 100's of LEDs but the reader is 
				happy with a simpler versions shown below containing 125 LEDs:
				
				
				The project requires each LED 
				to be individually turned on and off. 
				It's obviously the job for a microcontroller but the requirement 
				of 125 outputs is enormous. 
				The second point to consider is the programming. 
				Each LED will need to be given a value and you need to be able 
				to add all the values to produce a pattern for each 
				frame of a sequence. 
				Next you need to have some form of input to activate each LED.
				You may need 125 push-switches in a 3D arrangement with a toggle 
				on-off action to turn on the LEDs for each frame of the sequence. This will 
				involve another 125 "lines" or inputs. 
				You can consider multiplexing the whole display, but this 
				will decrease the brightness slightly. 
				It's an interesting project but very complex. 
				I don't have any simple answers. 
				Anyone with suggestions will be welcome. 
				
				
				
				
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              For now,
              
              Colin Mitchell, 
              Editor 
              TALKING ELECTRONICS Interactive.  
              
              
              
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