christhetrainguy09 posted:Grade crossing can be reduced to just one: If you're only allowing one channel for this feature you have to go old school and use a 555 timer to activate "flashing" LED's Timing is adjusted with capacitors on the 555 timers.
"Standard" , "Everytime" and "Enter-On, Exit-Off" seem the same to me, trigger is tripped item on, trigger off item off
Most of these can be done with a relay and isolated rail and a adjustable pot for timing delay.
For the grade crossing, yes, it could be just one, if folks want to have to add their own flasher circuit. There is no point in adding a 555 and associated parts here as the uP can do the job with no additional parts. In my mind, the version that has the flasher built in would be more useful to more people, and the mode that just turns on and off is a throw-in for folks that already have flasher circuits or signals that have them built in. To get a prototypical activation, where the signal turns on well before the train arrives at the crossing, but turns off shortly after it passes, requires two insulated rails, one on either side of the grade (for two-way operation, anyway). Since both inputs are tied up anyway, we may as well use both relays and offer a flasher.
Note that "Every time" is not a function, but a frequency option.
As for the enter-on, exit-off, this is different than the standard in that it uses two insulated sections. I'm a little confused on this one myself, but it was mentioned and has yet to be elaborated on. I expect this would be most useful if instead of using insulated rail one was using IR devices that have only a small detection area.
There are some things I listed separately that are really the same thing, such as standard and delay turn off. You get standard if you turn the delay to zero, for example.
JGL
