hi,
for such "permanent power ON" projects I preffer to use "reset-run-reset-..." technique with external watchdog installed. It was already discussed in the forum so try to search in.
In short: program sequence is divided into threads. After each thread has been done, MCU stops and waits for watchdog reset. After reset it starts to execute next thread etc. Indeed, it is not always appropriate solution; nevertheless it is very useful for many tasks.

Regards,
Oleg