Status: Waiting for prototype PCB boards...
I'm looking for an easier way to construct control panels. Drilling holes for buttons, LEDs and more LEDs is a pain. What if I could mount LEDs to the pushbuttons so that I only had to drill one hole per turnout - and maybe none for block occupancy. All I would need to do is fab a small circuit board that would hold the push button, the LEDS and something to drive them (a wiring harness or ...) Over the years, the idea has been bouncing around, but never getting too far.
As I was putting together the design for an i2c Arduino Shield, it all came together = a turnout needed 4 I/O lines - one for "switch position", one for OS occupancy and one each for Normal and Diverging. Add power and ground, a RJ12 connector and a couple of TC4428A's to drive the bicolor LEDS, and I'd have something with an extremely small footprint that would make building panels easy.
The thought is to use a plexiglass panel sandwich with a color-printed transparency gel of the track plan inside. Drill/punch holes for the buttons (and mounting screws), assemble the sandwich and mount it in a box, then assemble and mount the button boards to the plexi sandwich with their bezel nuts. As for wiring, each would get a short 6-conductor phone cord patch back to one of those IOShields mounted in the box, and the Arduino would get programmed to monitor the buttons and drive the LEDs based on Loconet or OpenLCB packets.
This simple board set has a turnout, a wye and a "single block" occupancy display. (I still don't have a good idea how I'm going to mount the last, maybe RTV Silicon or clear epoxy...
The following files can be downloaded