Is there a way for a Variable declared in the program to retain it's value if it is change and the arduino is turned off then on again?
Example is that if "X" variable is declared as 0 from the start of the program, and then it became "X=1", is it possible when you turn off/on the arduino
the "X" retains it value change which is "1" ?
Just a quick question to make sure, in the topic of powering the arduino,
HOW MUCH VOLTAGE WOULD YOU NEED TO TURN ARDUINO UNO ON IF NOT CONNECTED TO A PC via Cable?
Another possibility is check the peripheral chips you're using. Sometimes they offer a place to stash a few bytes. For instance, I use the DS1305 RTC in one of my projects. it has 96 bytes of user RAM that is battery-backed. No finite cycles to worry about. I think the DS1307 and others have similar. You could also consider adding a Serial ROM chip.