aarg:
What happens when the train reaches the end of the track?
The site that has the 555 circuit explains it, but the simple solution is that it runs until it hits the diode in the track and waits for the power to be reversed.
If it takes 30 seconds for the train to traverse the track, you put in a run time of 40 seconds each way. That way the train sits idle for about 10 seconds at each end. Long enough for human attention to move elsewhere on the layout, giving a sense of realism that is missing from small loops where the train just goes round in circles.
http://home.cogeco.ca/~rpaisley4/AutoRevCheap.html
I was trying to put this into the wiring diagram but I could not remember which way the diodes pointed.
And I found the link to my proof of concept work. The line will be a bit longer when we put it on an layout. And rather than commit my $35 Uno, I wanted to use a $1.38 ATTiny85.
