gunrunnerjohn posted:...Stan wants to automate it so you just pick a track and everything happens behind the curtain.
I'm still on the case. RJR's comments about watchdog timing got me thinking. Like he says, why not have the watchdog in the yard on all the time? So my latest scheme:
Use a DCSRC passive-mode powered by a relay that continuously turns on and off once per second (using a homebrew 555 timer or an eBay cycle-timing module for $1-2). I just checked and a DCSRC will generate a watchdog after a power interruption of a fraction of a second. This will put a watchdog signal on the track once per second whenever there is yard power.
Now you can rotate the selector switch directly to the desired track without first going to the off/home position. And within one second, the newly powered track will get a watchdog signal and the engine will come up silent in command-mode.
The bonus of this approach is the track bumper LED that indicates to the user which track is active never blinks OFF as it would for any scheme that momentarily cycles track power to a passive-mode TIU.
