Hi
I am trying to input data using 7 switches connected to the parallel port. I do not know much about elektronics , and i put together a small circuit which does not work correctly. It was based on several parallelport - interfacing howtos i found in the web.
Three switches are connected to Pins 11, 12, 13 like this :
pin ---------o-|R 13k|--- +5V
|
o--switch--- +- 0V
Four switches are connected to Pins 1, 14, 16, 17 :
pin ---------|out Inverter 74LS05 in|---o--|R 13k|---- +5V
|
o--switch----- +- 0V
(I read somewhere that would be useful because these 4 pins are 'open
collectors' and the 74LS05 would act like a driver ) Now the problem is, that
the four switches connected over the inverter do not work (they do not
influence the values i get from inb(baseport+2)). Could anybody help me ? Maybe
the 13k -Resistors are to strong ? Or am I totally wrong with this circuit ?
Please excuse my bad english ;)
Daniel
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