Hey, i have a problem that i have been at for over a day now, and i can not solve this with my skills. So the problem is as follows. I am trying to get an output from a 4x4 keypad, which would not be a problem but input and output are on the same pins. I know that the 74hc573 should keep the information after LE goes low, but i just can not figure out how to read output from 74hc541 without giving new information to the previous chip, because then the state changes again. At the moment i can only read the keys diagonally, because input and output match in that case. The schematic of the whole circuit can be seen here
:http://i.imgur.com/FWcJRvP.png and the problematic part here :http://i.imgur.com/i7vwFXs.jpg
Hope you guys can give a tip and help me understand this. Thanks
Actually the circuit is pretty well designed
If you have to jump through hoops to do something as simple as scanning a 4x4 matrix, then it's not a well designed layout.
But anyways, this is not in any way, shape or form a Keil related question.
I turned here because i really needed help, and did not really know where to go. Since it is related, i did not think it would be that much off. Sorry for bothering you