I’ve been running my lower power arduino using the narcoleptic library for several days now and I keep finding the arduino hung after several hours.
Today I put in code to display where I am to a terminal to see where the hang occurs.
I discovered that the arduino was actually rebooting after several minutes. I removed the call to Narcoleptic.delay and the problem went away.
Past experience with random reset/reboots like this has been caused by the power to the arduino not being clean enough. For the heck of it I put a 47uF cap across the +/- of the 5V power supply. Sure enough no more resets with the capacitor when calling narcoleptic.delay.
My theory is that when the watch dog timer restarts the CPU, it creates enough of a drain, or perhaps some noise, that the normal RBBB caps can’t handle and the controller resets.
Now it just needs to run long term again to see if that fully solves the hang issue (I never saw it actually hang while I was monitoring).