The recent Model Railroader/Arduino promotion of a MRR-specific Arduino beginner kit got me started on this.
I have two Z-Stuff for Trains signal bridges with semaphore heads, and bought extra heads to have two heads on each mast to serve a straight and diverging route for each track and mast. Knowing these heads have micro servos to allow for 3 position R/Y/G aspects, and their basic controls operate only on a timer for the duration of the yellow after detection ceases, leads to my question.
The first question should be is this a fool’s errand, so comments in that vein are welcome.
I’d like it so that each mast would show high green for straight and permissive, and a lower head yellow as the only permissive. Detection could be directed from the correct outgoing track by switch machine contacts or a relay using a length of isolated outside rail on each track. Likewise, contacts or relay would act in the same role as detection to make the route not chosen’s head go to red.
Then, how to tell the lower head that yellow is its permissive and eliminate green/vertical? The straight option would stay with detection triggering red and timer function for return thru yellow to green, so the head wired through the bridge by Z Stuff becomes the one mounted high.
I got to wondering if Arduino has one solution for this, but have no idea if that would be the best rabbit hole to go down trying to solve it, or a better way exists. The semaphore heads are important since this is the throat of my C&NW Chicago Passenger Terminal with its famous semaphore bridges. Pushed to complete simplicity I’d have to do something basic and not very “interlocked”, just to keep at least one functioning semaphore per track.
Has someone else played with this situation?
