storing names and numbers to keep after powerdown

i want to be able to allow on first startup to store a user's name and about 6 phone numbers. but i want them to stay in there after power down so they can be used in the program afterwards

the details will be entered via a touchscreen and then stay there until requested

What Arduino model? - Not all models have built in EEPROM memory that will preserve data across power off.

How much data? - The UNO only has 1K (1024 bytes) of EEPROM memory available and other models may have more/less.

How often will it be changed? EEPROM memory is only good for about 100,000 times writing (lots more reading) so if the data changes much the memory will not last long before you get write errors.

You could also use an SD memory card with suitable adaptor.

Somewhere on here I have seen someone testing a new bootloader that allows the flash memory to be altered during normal program execution (usually this can only happen during bootloading) so you might be able to find/use that.

i have a mega 2560 and also there will be a Adafruit touch screen with SD card and maybe only 5 to 10 times the data will be changed in its life these will be semi permanent values once set

mikewitney: i have a mega 2560 and also there will be a Adafruit touch screen with SD card and maybe only 5 to 10 times the data will be changed in its life these will be semi permanent values once set

The mega has 4K (4096 bytes) of EEPROM memory so from what you describe about a user name and 6x phone numbers, this should be fine. Just use the EEPROM library and maybe other helper libraries (something like this) that will make it easier to store/read char arrays. Might also be worth doing other Google searches as this might be right up you street.

As you also have an SD card reader built into the screen that is also an option. You will find lots of examples of opening and reading files from SD.

thats brill thanks

reading up on all this read and write to eeprom is a little scary knowing i can burn out the eeprom just by writing too much by the time i have debugged my code i may have done quite a bit of damage

i think i might go down the SD card route knowing i wont damage my board