David Duffy (AVD) wrote:
> The main reason the EE was used was to persist the unit's status if it
> was power cycled,

How about keep the live value in RAM and write it to EEPROM only on power
down?  It only takes a few milliseconds to write to the EEPROM.  You need to
detect input power going away, and have a large enough cap on Vdd to keep it
running for the few ms it takes to detect the power gone signal and save the
live values in EEPROM.

As a quick example of the cap value, let's say it needs to provide 10mA for
10mS with no more than 1V droop.

  10mA 10mS
  --------- = 100uF
     1V

You probably have that much on your power supply already.


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