dorchfc

As both a signalling engineer and a model railway enthusiast with some Arduino experience, I found the way to go with the NX panel was to use the button press to set a software latch for the event of entrance or exit button. If you start with a latch for Entrance pressed as well then next button has to set the Exit pressed latch as well as setting individual latches for the relevant Buttons. When the corresponding ENT & EXT signal buttons have been pressed I move points by means of a relay as I have Cobalt point motors, they could feedback over the contacts so the Arduino can give point indications. When a route is set I also set a route latch that can be used to inhibit conflicting routes. The Arduino provides outputs to the main aspect and rout indicators of the signal as well as red/green on the NX panel and route lights. For a simple 2 route signal into a bay platform and a through platform with input from the next signal on the through platform to give the third aspect input and 2 platform starter signals my code reached 190 lines and utilised 22 I/O pins and has 9 latches using bool functions. My station area alone would need either a dozen Arduino Megas or huge number of I/O extenders, After the first 3 signals were created and tested I realised the folly of this method and starter to device a lever frame option using microswitches and servos in the frame to provide 'locking' of the levers.