Searching for this topic on google comes up with a number of threads, however none of them was conclusive or I was unable to understand what the final recommendation was!
Current situation :
I have a number of working sketches that use the onboard eeprom on 32U4 or 1284p MPUs to store settings for my sketches. Having decided to move to an ARM MPU I now need to “port” these sketches to work on an arduino zero clone type of board but I need to find a replacement for the functionality of the onboad EEPROM that does not exist on ARM MPUs.
As for hardware, I seem to have two options:
- My custom PCB also has a place for an external I2C connected EEPROM
- EEPROM emulation of the MPU’s flash memory
Does the fact that the contains of this “EEPROM” must be maintained even when the program is re-flashed crosses out option 2 above?
If now option 1 is implemented, whats the easiest way to use my existing sketches and somehow “re-direct” access to external I2C eeprom when the sketch is loaded to an arduino zero board but also maintain compatibility with the AVR boards?