# Led Diode BillBoard



## MicroBoy (Sep 28, 2008)

*I want to make a Led Diode BillBoard for my self, but I don't know very mutch about it. Can anyone tell how to? Or just to post a software that can help me?*


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## Done_Fishin (Oct 10, 2006)

you aren't asking for much .. 

in brief you will need to create an array of LED's in a form that can represent a character or number. I am trying to remember what the normal format is, I seem to remember it's similar to the printer dotmatrix 8 dots wide by 7 high, so possibly 56 diodes per array

you will need to decide how many characters you want to display at any one time and create that many arrays 

you will need to have a buffer that will be used to select each individual array and another couple of buffers which will be used to select the horizontal / vertical matrix 

you'll need shift registers & latches to catch the data and then shift the data sideways so that the data runs ..

you'll probably get away with using BASIC and your parallel port to send the data as ascii format to your billboard 

I would suggest though that you first get one character array working then slowly increase towards your billboard and running effect 


a simpler effect would be a counter to make one or more led's light up in clockwise or anticlockwise fashion .. without using a PC.

and should you use a PC to drive your billboard .. use opto-couplers to isolate billboard voltage / psu from your PC .. in the event of an "accident" you won't be looking to buy a new PC


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