Thinking ahead: Detecting which way points are set

[paul1066]

I've been putting in my very first colour light signals which have a simple IR detection in the track and change aspect on a simple time-based program once a train passes the signal. All well and good, but I've been wondering about that else is possible, in particular the possibilities of a signal showing red if a set of points is set against a road, or an "arm" illuminated on a signal if a particular road is set. I've a basic beginner's understanding of how systems such as Picaxe and Arduino work (very much enjoying Rudy's videos BTW) but what I've said above would require any system to "know" which way a set of points is set. Is there a particular approach that is usually adopted for this? I've a DCC set up with electrofrog points and simple throw switches to activate the seep points motors - nothing more fancy than that, so to my simple brain the obvious solution lies in the points frog which changed polarity depending on what way the point is set. Thanks Paul

[Steve M]

I have already done something similar without, I hope, over complicating things.
I use Gaugemaster autofrog to take care of polarity switching for the frogs - cheap, simple and idiot proof. I use the inbuilt switch on the Seeps to switch between red and green lights on both a mimic board and LEDs fitted to ground signals.
Job done.

[Tricky Dicky]

The only sure fire way of detecting the points moving is to monitor the movement of the tie bar with a micro switch, inbuilt switches on point motors or micro switches attached to the point motors. Anything else simply tells you that a switch has been thrown/pushed but does not guarantee the point has actually moved.

Richard

[paul1066]

Kinda what I was thinking, still plenty of time before I need to do anything yet.

[RAF96]

I concur.

Switch should be operated by the point motor, hence if point moves the switch moves and the attached light tells of switch situation.

No point having the light on the operating toggle/push button switch as if the motor fails to follow the command the light tells of the selection not the point position.

Rob

[steel bat]

I have seen advertised on ebay a little circuit board which "remembers" the last way a point was energised - which might be easy to install in the control panel to light LED's - but would have exactly the weakness Tricky Dicky and RAF97 mention of not detecting a failure of the point itself.

[paul1066]

Had a few thoughts about signalling and points and will be trying out an idea sooner than I thought! I do have a switch built into the seep points motor but it's already used to change the polarity of the electrofrog so my approach will be to use a microswitch that'll be activated by the bar running through the points motor that activates the points - it protrudes out of the points motor (below the deck) a bit fiddly but should work... I will report back with any update!

[Steve M]

Paul, the switch on the Seeps can be unreliable - I wouldn’t rely on it for frog switching. As you are DCC look at an alternative such as the Gaugemaster autofrog GM80 (I think). That will leave the switch free for signals or mimic lights which are less critical systems.

[paul1066]

Steve, no problems so far crossing fingers, but if I do have a problem then that solution you suggested looks like a sensible way out - thanks for pointing it out. I'll probably change them over as I add stuff that relies on point switching.

[Steve M]

You’re welcome Paul. I started off using the Seep switches for the frogs but changed as soon as I could - haven’t looked back.