> A typical method is that the routine always runs, and when
> the user presses a button it outputs the current value in the
> sequence.  Ok for a dice rolling app, not so good for
> something that doesn't have any inputs

An analogue function "input" in all PICs is WDT. It's
temperature-dependent and not connected at all with the
digital parts. An application I keep meaning to try, but
never get around to although I know it will work, is to
measure WDT to a fine degree, with a heated resistor
changing the temperature of the PIC. Even a degree is
enough to change the last few decimal places

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