I would go with a standalone design & skip any regulators, LEDs, etc that draw power & don't do anything for you.
Look at smaller parts too, ATTiny13, since you don't need a lot of IO.
I would go with a standalone design & skip any regulators, LEDs, etc that draw power & don't do anything for you.
Look at smaller parts too, ATTiny13, since you don't need a lot of IO.