cptr05

The issue I have isn't detecting the if there is a train but more what train it would be if i use battery power because you can isolate tracks on the 9v system and control those individually. and I am planning on using a raspberry pico W or some Arduino if I every need that for some reason. a bar code or something like that under the tracks is a cool idea but getting a lens that can see and focus at those distances (under the track) would be very hard. if i were to do that I would go the vision route with a rasperry pi and cameras but that is WAAAAY outside my comfort zone. So adding a sensor to the train wouldn't be ideal because i would have to mod them and it wouldn't look as nice or maybe a sensor that faces down that looks for color in the track? (like this?) but than i would do it the other way around and have a sensor that looks up from the track and i currently have 1 9v train and 4 power functions train (i could upgrade them to powered up just need the hub and motor) but i want to start small and add stuff as I go on but i wanna make the best informed decision on what I should get invested in so i think power functions is out because you need (almost) direct line of sight and its older than powered up this could work but I think this gets really complex the more you scale and if you have multiple trains on the same loop in the same direction so using the magnetic thing you wouldn't have to think about ambient light and that is really cool so that could be a good alternative for a LDR using the 12v system isnt really in my mind but also not a terrible idea I just haven't really looked in to it but its really old but less used as far as I know and thanks for all the feedback!

so I want to automate train. I just don't really know where to start. because I think I have 3 choices 1. 9v trains 2. power functions 3. powered up so the 9v system is really easy you just need a train a micro controller and a motor controller. but it is getting really expensive. I do have a lot of power function trains but automating them with IR leds way to seems hard and they are retired now. and powered up uses Bluetooth which you can use with an Arduino. like power functions uses batteries, i don't like that but unlike both this is new. so the easiest choice to me seems 9v but i only have one 9v train and 4 power function trains and way more RC track to. but if i go with battery power how do I know where a given train is. with 9v this isn't an issue because the track can be on or off. so is there a way to detect battery trains if you have multiple on the same loop? or would it be easier to go the 9v route and have to use decade old hardware. or is there something new with the powered up system that allows me to do things that i wasn't able to do with 9v and or power functions