Model Railway Forum

Hi, is there anything out there where I can track the position of a specific train on the layout & have it show up on a mimic board with a diagram & led’s. It would need to be for a maximum of 4 trains. This is on a RC layout, so no voltage on the track. Possibly something with its own code on the train that transmits to something beside the track when passing.
I thought of reed switches & infrared, but thought there might be a better alternative? Thanks
PS: The track is around 40met long X 2 tracks in three rooms. This was the need for tracking the locos.

What you are looking for is track occupancy detector, so that is the key phrase you need to search for. There are no shortage of these on the market, but usually they require some sort of electrical connection between the loco and the track. Typically they will sense the increase in current in a section of track.
If your track is metal and the loco wheels are metal there are simple circuits that can detect a short circuit when the wheels pass over an isolated section of track. Another option is to use some sort of magnetic detection an infra red detector, examples in the links below.

http://www.rr-cirkits.com/ir-detector.html

http://www.gatewaynmra.org/1997/easy-bl ... -circuits/

Thanks for that. But unfortunately when i first started, all the tracks where soldered together as i was going down the DCC route. There might be an alternative if i could adapt one of the model car transponders that records lap times with a transponder. Each transponder has it own unique code.
All ideas & alternatives at the moment are welcome.

I use both reed switches and opto sensors for train detection but I don't see how you could easily use these to detect specific locos which is what you are asking for.

The only way that presently comes to mind is to have two reeds, one high (just above roof level) and one low at track level. To detect up to four trains you would also need an opto sensor. The opto sensor would detect ALL locos. Then place the magnets in the locos as follows:

Loco 1: No magnets
Loco 2: One low magnet
Loco 3: One high magnet
Loco 4: Both high and low magnets

I believe there are DCC systems that can detect specific locos.

RFID tags and track mounted readers are one way of both real time positioning and actual loco type detection.

Gamesontrack is a commercially produced GPS system https://www.dccsupplies.com/cat-223/gam ... ontrol.htm

Hi Brian, thanks for the info, the RFID route is very nice idea & the other a bit expensive. Out of curiosity, have you seen a 4 coloured LED. Have seen bi/tri but not quad.Thanks

collectors wrote: ↑Sat Jul 24, 2021 1:06 pm <SNIP> Out of curiosity, have you seen a 4 coloured LED. Have seen bi/tri but not quad.Thanks

Yes, but mainly those I've used are not colour controllable. they are randomly colour changed e.g. Link to LEDs

That said controllable ones are available, but you need a device e.g. Arduino to control them Colour change LEDs

Brian wrote: ↑Sat Jul 24, 2021 6:45 pm

collectors wrote: ↑Sat Jul 24, 2021 1:06 pm <SNIP> Out of curiosity, have you seen a 4 coloured LED. Have seen bi/tri but not quad.Thanks

Yes, but mainly those I've used are not colour controllable. they are randomly colour changed e.g. Link to LEDs

That said controllable ones are available, but you need a device e.g. Arduino to control them Colour change LEDs

Will use 2 led's instead. Thanks