Good day,
I am thinking of employing 1 or 2 Rpi's into my model train layout to remote manage my turnouts and other specialty items on my layout.
I know through GPIO-P1 I have 17 available GPIO pins. From some of my other reading I have discovered on the new model B's there was a P5 added that gives 4 more GPIO pins for usage, but it also says in the same document that those pins are used by the system. The available pins on P5 are GPIO28-GPIO31, but those are used as follows: GPIO28-31 are used by the board ID and are connected to resistors R3 to R10.
I know that some are also avabile via S5 which from my understanding will eventually be used for the upcoming camera board.
So if I read correctly, theorietically I could have 25 possible GPIO pins available or would it only be 21 if I take and use the 4 from S5.
Any input on this from others would be great.
Thanks
Terry
