Store some configuration on the SD Card

[chrisroos]

I wonder if it'd be possible to store some of the configuration, e.g. printer server, MAC address and printerType on the SD Card? This would avoid the need for each person to compile their own sketch but at the expense of a little more complexity in the code, and potentially more complexity in general. What do you think @lazyatom?

[lazyatom]

I think that sounds really interesting. It's definitely annoying to have to retype the MAC address into the sketch for every board; that's probably the most acute pain I'm feeling at the moment. It's possible that could be generated and stored either on the SD card, or in EEPROM with the printer ID.

We'd need to think through how they'd initially be written to the SD card, and how a user would edit those values.

When I first read this I'd wondered if storing the printer ID on the SD card made sense, but then if the card was wiped, they'd lose the ID completely. So there's some thinking about data permanence required too.

Another approach could also be to provide a web-based way to generate the sketch based on values selected from a form (or stored in some 'account' on the server), and then each person could just download "their" customised sketch and upload it? Then the server URL at least could be automatically populated...