At the ‘Fun with Arduino‘ blog I posted an article on an Arduino sketch for a two track two way railway crossing, with blinking LEDs and a servo controlled beam to close the road.
There are more sketches available over there that are suitable for Model Railways.
Such as the Station Platform Clock and Train Departures Sign that uses a small OLED display.
Or such as the (timer) control for LEDs that can be used for house- or street lighting.
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