expanded parallel display

Joined
Sep 7, 2004
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695
is there any reason why this would not work (with proper coding):
expdsp.jpg

i want more then 8 leds... and i cant find my pic programer :confused:
 
theshadow27 said:
is there any reason why this would not work (with proper coding):
i want more then 8 leds... and i cant find my pic programer :confused:

That should work alright but there is better ways of hooking the different shift registers together. The easiest way is to connect all the clocks together and all the latch wires together and then connect the parallel port to the serial in pin of the first 74HC595. You can then connet the serial out of that chip to the serial in of the next one. This would scale indefinately. The only downside is that your update speed will drop as you add more chips.

An alternative to the diagram you drew is to connect all the clocks together and use unique data pins instead. This will involve the same number of wires as your diagram but allow you to load the chips much faster.
 
The Brain said:
An alternative to the diagram you drew is to connect all the clocks together and use unique data pins instead.

duh :eek:

it is a parallal port after all

that is a MUCH better idea. idk why i didnt think of that. thanks mate
 
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