Input and Output in only a few cables...

Other Hardware LEDs and Multiplexing
1

Hi

I have a project where I need to run 12v thru a few relays. I also need to be able to check the status, so basicaly I need a full input/output

I can only use RJ-45 (8 pins) between the two places. So I was thinking of using 1 pin for 12v, 1 pin for GND so I have 6 cables left.

When I use Shift Register, I need 4 cables for the input and 4 for the output... So this makes 8 only for the data plus 12v + GND...

Is there a way to optimize this so that I can send all this thru 8 pins??

I saw a few person that said to use shift register, only with 3 pins? Maybe?

Thanks!

Steven

2

Sure, 2 shift registers even: Clk, Data Out, Latch-Out, and same Clock, Latch-In, Data In.
74HC595 for output if you don't to drive much current,
74HC165 for input.

3

CrossRoads:
Sure, 2 shift registers even: Clk, Data Out, Latch-Out, and same Clock, Latch-In, Data In.
74HC595 for output if you don't to drive much current,
74HC165 for input.

Thanks for the quick reply

Just to be sure, you are sharing the same pin for the clock only or the 2 others also?

So it makes 5 pins: clock, latch in, data in, latch out, data out?

Thanks!

4

Clock only.

5

CrossRoads:
Clock only.

Awesome, thanks so much!!! :slight_smile: