All I’ve been really looking at Arduino. High amp motor shields can be found cheap. Many of the the 10amp to 30 amp motor shields already have a regulator - you’d only need to put a bridge rectifier to go from ac to dc and ( 20v-40v ac) .
What I’m trying to figure out is how our smoke unit fans are controlled. Is the smoke unit fan like a servo or is it a continuous motor?
One Arduino can control up to 12 servos - that would definitely take care of couplers and lights.
I still think Arduino with a motor shield and Bluetooth card is a good option - apparently 7” backyard hobbyists have been using this setup.l for a while.
Adding up the components would be about 30-80 dollars a train. Most of the cost is dependent on where and whom you bought components from.
There already is quite a bit of forums posts about interfacing dcc and arduino - or just using arduino and custom code to run switches and signals.
I haven’t stumbled across tmcc and arduino projects, but that’s probably due to dcc being a larger hobby base.
If I try this, I’ll probably attempt this on one of my Williams by Bachmann engines.
If anyone beats me to this experiment, my only advice is to get a separate Bluetooth card and not try to use the low powered built in Bluetooth of a Arduino nano. 150 feet of range or more has been reported on the forums I’ve read.
if you want a pretty developed interface on an Android tablet and already working code look at Steve’s site ( https://arduinorailwaycontrol.com/ ) . Steve is very responsive to emails and his YouTube’s are tantalizing at what’s possible.