So what do you do when your control panel needs more than the 26 GPIO pins a standard Pi makes available? You use the train control program control.py in client-server mode, of course! I just checked in changes that allow multiple Pis to slave off of a server Pi that has the connection to the LCS SER2.
Examples are coming, but this development will allow stand-alone control panels to be built, powered by an inexpensive RaspberryPi with WiF. All wiring, except for power to the Pi, can be managed inside the panel enclosure.
-- Dave