G'day again, I have a Vdrive that I can read/write too and ever-things Ok until I turn off the power to the arduino (inturn the Vdrive as well) Even when I reload the sketch the Vdrive keeps flashing. But when I load another sketch (a scaled down version of the first) the Vdrive is Ok again. And then I load my first sketch again and all is still well. So my question is: - Is there any EEPROM that can be written by a sketch that is not altered when the sketch is reloaded. Or put another way can one sketch set EEPROM, and another sketch clear it. Hope my description makes sence.
Any sketch can write to EEPROM, and any sketch can read from EEPROM.
Loading a sketch does not affect EEPROM. It is completely separate memory.
However, it is not clear what storing data in EEPROM is going to do to solve your problem. There is a limit to the amount of EEPROM available, and some limits on the number of times you can write to EEPROM.
Do you have a link to information about this Vdrive? What you you mean by this?
Even when I reload the sketch the Vdrive keeps flashing.
How does loading a different sketch affect the Vdrive?
I would look at (and possibly add to) the VDRIVE initialization code. It is required that you request and read all status codes during startup and (if my memory serves me right), flashing suggests you're not reading it all.
As a test you may try to load your "primary" sketch and if it fails to communicate with the VDRIVE, just keep pressing reset (to rerun the startup code) and see if it eventually will reset VDRIVE to ready status.