How to store long term data

I am creating a sketch that controls 6 servo's.
I have three values for each servo "limits" that need to be stored after power off. A total of 18 values, of 3 digits (0 to 255)
I load the sketch with defaults and then trim the "limits" with an LCD screen to the physical limits of the end device.
I need these values to be saved after the power is cycled. I know I could put them in the eeprom but seems like a waste as they are not dynamic once set they are a static value for ever. can I save them back into the flash-memory stored sketch without a PC?
On my 3d printer I can change feed rates etc and then "store" them. I want to do the same thing.

my data is stored like this at present.

int table[18] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; // Servo data limit array

I call these limits using the index value as required.

I dont have a huge programming knowledge I learn what i need to to achieve the outcomes I need so go easy on me.


That is really what your EEPROM is made for and that’s easy… Why would it be a waste? Are you storing anything else there?

no nothing else, but it is prime realestate in the nano, if there isnt a need to use it then it stays free.

But i am detecting that this may be what I do and be done with it.

It is there to be used even if it us prime real estate... You paid for it when you bought your arduino, so nothing wrong using it for what it was intended too.

Also you write only once if I understood correctly so it is not like you will kill that memory space (limited to 100,000 write/erase cycles)

There are ways for programs to write in the flash space if you play with Boot Loader Lock Bits. See that post for context - but I'd say it's looking for trouble.

It's not a waste to put them in EEPROM - this is exactly what it's for. Only caveat is that EEPROM isn't for thing that change frequently. But for data holding the configuration of your physical setup it's exactly the right approach.

Prime real estate? If you don't put numbers in it, it's sitting vacant, and you know how bad that is for the market! :o For God's sake man, populate those addresses!