Write to EEPROM directly

Greetings Arduinians.

i was wondering if there was a way to write to the Arduino EEPROM directly. I would like to design a shield of some sort that could edit the EEPROM without the need to load another program onto the chip.

A bit like the famous tinyG-shield that takes over your arduino. Whatever sketch you have on your arduino is left there. The ports are hijacked.

I would love to know if this was at all possible with the MEGA.

Thanks for your suggestions.

The EEPROM can be accessed by using a Programmer that connects to the ICSP pins - Reset, SCK, MOSI, MISO. The sketch upon restarting can then act on the values in EEPROM.

Or, the shield can talk to the sketch and give it new values to write to EEPROM, etc.

Thanks mister CrossRoads,

Do you know where I could find some documentation on that… Could it be done with a second arduino?

Most definitely it can be done with another Arduino. Load the "Arduino as ISP" example that comes with the Arduino software and follow the tutorial on the Arduino website to see how to hook it up.

Basically the "Arduino as ISP" takes serial commands and converts them to the In-Ssytem-Programmer format to read or write the other Arduino's memory.

Waw thanks Morgan, didn't even notice that example sketch before. Strange how somethings can be right in front of your nose :)

So thanks I'll give a holler when there is something I can't figure out, but as far as I can see everything is there and first experiments look promising!

Cheers.