Using extra IO ports in Marlin? (4 replies)

Hi,

I am using a melzi, a sanguinololu-based board for my next reprap. I would like to use some pins on the expansion header for digital IO.
In particular, I need two inputs, an emergency-off switch, and a Z-min switch. I would also like a digital output to control my ATX power supply. What do I have to do to configure the expansion pins to be inputs and outputs, so that I can configure them to be used appropriately in the pins.h file in Marlin?

Thanks,
David