Now, this is going to take awhile, so if you've got an hour or so to kill, and you're familiar with electronics and Arduino, this modeler's experiments will be fascinating: (oh, and despite the accent, he's in the US). Channel name is "Internet of Toy Trains" and he's very thorough in explaining his development progress. Even though I don't know much of the tech he's using, I was able to follow well enough to realize the possibilities he's exploring. There's a lot of videos on his channel, and even though he's primarily a G scaler, he's adapting his work to be useful in HO and N scale, so using parts of his developments in 'O' shouldn't present any problems. This selection is building up to something, so a bit of patience is in order.
First off, the use of Hall effect sensors to perform track distance measurements (this is about two years ago, and runs 17 mins):
Okay, you might be thinking "MTH's ProtoSound 2 and 3 do this via their odometer and command-mode scale MPH, no?". Well, yes, but can you use this data in real time to measure your layout? Ahhh... we're starting to get into something, as the video title suggests. As reflected in the thumbnail below, about halfway through he tests out his project on a garden railroad with an inset showing how the device, communicating with a program on his PC via WiFi draws out a map of the layout in real time. (also about 2 years ago, and 20 more minutes)
This last video is the first one of his that I ran across, and I spent hours watching the developments leading up to this that I should have been using amidst this long weekend to upgrade my main laptop from Win7 to Win10 (yeah, I know about it's EOL). Those who have wrestled with signal wiring will find this interesting (posted a day ago as of this post, and about 13 minutes) and the above videos lead toward this:
If you're just skimming across the topic without watching the videos, the sum total of all this looks to be working toward the potential to build what amounts to a Positive Train Control system for model railroads 
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---PCJ
