HD44780 address calculation error for some displays

[Sh4rK]

Hi!

We are using a HD44780 compatible display in our project. It is a 4x16 display, marked "1604A". We found out that the current address computation is not correct for this display. The correct line addresses are: 0x00, 0x40, 0x10, 0x50. I made a quick patch to make this display work, but it breaks current functionality: https://github.com/Sh4rK/xpcc/commit/52998df0f776caf3d9e83c4a26e10f8b317c422a.

Unfortunately I don't have any other displays to test, and I have no experience with them, so I don't know how to write a generic solution that works with everything, or even if it's possible. Maybe the only way would be to take some additional parameter(s) that describe the address calculation.

[salkinium]

Hm, in that case I would suggest wrapping the address calculation into a (stateless) function and passing that into the constructor and default it with the current implementation. That would be backwards compatible and you can add yours. Alternatively as a template argument, but that’s a bit verbose.

I think I have some hd44780 displays lying around, I’ll give this a try. The calculation may only haven been tested on dual displays /o\