38 KHZ detectors and arduino boards

I have successfully used reed relays mounted trackside with magnets on the trains to activate signals where IR was troublesome.

The 38khz pairs should be much more immune to the room lighting, I'd give those a try.

This should get you started...

http://www.robotshop.com/letsm...-collision-avoidance

Thanks for the info I believe I will order a few and start experimenting with some circuits. After adding everything up the price for making up the signals and controls should be less than $10.00 apiece for a single head.

Note that the IR transmiter module you show is "just" an IR LED.  Like it says, it "can send" 38 kHz modulation but you need to provide this 38 kHz modulation signal (pulsing or whatever you want to call it).  Just be mindful that the code examples given usually show a task in isolation - showing just, for example, how one might modulate the LED at 38 kHz.  If you determine the modulation burden affects your application, there are low-cost eBay IR transmitter modules that do this pulsing on-board.  So you just supply power (5V DC) and possibly a simple digital on/off to start it modulating...can't get simpler than that!

Here's a photo from this recent thread showing some of these combo transmit-receive modules; there have been other similar OGR threads if you use the Search function with relevant terms.  Obviously you can use just the transmit half of these modules and separately use a different receiver module.  If you use a combo module and wish to separate the transmitter (2-pin LED) or 38 kHz receiver (3-pin black windowed chip), you should always extend wires to the LED rather than to the receiver.  It's only 2 wires to run but more importantly the receiver chip, being a high-gain device, is much more sensitive noise picked up from the extension wires.

To your original question, using 38 kHz IR detectors will absolutely, no doubt about it, increase immunity to ambient room lighting effects.  With one qualification.

There was a curious situation several decades ago when Compact-Fluorescent-Light bulbs first came out.  These bulbs pulse the tube at high-frequency (much faster than the 60 Hz of traditional fluorescent tube ballasts).  Problem was if you used a CFL bulb in the family room where the TV was, the TV remote stopped working.    Most TV receivers have from day 1 used essentially that same 38 kHz receiver component you show.  Suffice it to say the CFL manufacturer(s) resolved this very quickly - changed the modulation frequency.   So I suppose there's a one in a zillion chance you happen to be using one of these old CFL bulbs in your train room for ambient lighting in which case you'll be in for some head-scratching!

You might also be interested in this topic:

https://ogrforum.com/...c-turnout-controller

I use a slick little self contained IR detector on some of the turnouts. They just need power and ground, and provide a logic level output indicating signal detection. I posted some details and a pic here. They take some time to install, but they drop right in between the rails like they were designed for it.