Initial values for non volatile memory

Projects Programming
1

I'm struggling with this question for a while, thought it can be useful for everyone, almost feels like I'm missing something, lets say I have a project integrating a temperature sensor, and an EEPROM memory-chip, with a simple goal in mind to to keep track of the temperature limits, min and max ever measured, of course it must be done with constant comparison of current temperature to what was min\max earlier and update if needed:

...
if(currTemp > maxTemp){
   maxTemp = currTemp;
}


if(currTemp < minTemp){
   minTemp = currTemp;
}
...

now keeping in mind that maxTemp & minTemp both stored on EEPROM, so I understand they just have to get some weird initial values (for example min=100, max=-100, such the values will be instantly updated on the first measurements) flashed on EEPROM before the program starts for the first time?
so I actually need 2 programs when the first only flashes the EEPROM so it won't hold garbadge values that will make the comparison fail? or is there more elegant way of doing this? :o

2

or is there more elegant way of doing this?

If in setup() you test for a specific set of values in EEPROM, say a string such as "PREPARED" and only if it was not there wrote the string and saved the 2 initial values then next time the program was run or reset the string would be there so the values would not be overwritten

3

UKHeliBob:
If in setup() you test for a specific set of values in EEPROM, say a string such as "PREPARED" and only if it was not there wrote the string and saved the 2 initial values then next time the program was run or reset the string would be there so the values would not be overwritten

nice, so the solution is to test for a token which won't be on a new EEPROM and if it's absent then the program will know to write it, then and give the init values on EEPROM , and for the next time of power on the token will be written and the program won't reset the values. You are awesome!

4

A new EEPROM will have 0xFF in every location but it is probably not a good idea to rely on that, so writing your own flag value(s) is a better idea. I suppose that you could check that every EEPROM location was set to 0xFF as your "never been used before" indicator