Making a permenant change at runtime?

Hi, ive read where people have wanted to "update" the firmware on arduino's at runtime which i understand is not-so easy without a modified boot loader, but i dont think thats what im wanting to do.

I have a few vars that are set in setup or "first thing" but what i would like is to change that var and have it be remembered or made permenant so when the arduino is powered down and back on the var is changed?

Is this possible?

Thanks
Andy

yes, but then you'll need to write their values to the built in EEPROM, and read them backt in when the program starts.

variables in your code will always be reset when the arduino resets, there's no way to keep them without storing them somewhere.

you can find more info here