Viki2 lcd panel on Maestro
I have a Viki2 lcd from Panucatt Devices from another project and a Duet 2 Maestro on the way and I would like to be able to use the two together.
From looking at the datasheets it appears that the 12864 lcd used in the Viki2 differs from the 12864 lcd used the the standard reprap graphic lcd. The primary difference looks to be the need for a A0 lcd register select pin on the Viki2 lcd and the software support to use it when driving the display.
Can support for the Viki2 be added to the firmware wish list?
Do you mean that the Viki2 needs an extra signal from the Duet? Are you certain that the extra signal is needed? If the Viki2 uses the same ST7920-based LCD as the other displays, then it should only be needed if the display is driven in parallel mode.
12864 displays for 3D printers are very cheap (I just found one for £7.12 on eBay UK, not much more than 2 pints of beer), so if you can't get the Viki2 working then I suggest you buy a new display.
Alternatively, for just $5 more than a new Viki2 from Panucatt, you can get the much more capable PanelDue with 4.3" screen.
From looking through the documentation and looking up it's use with other firmware it looks like the Viki2 uses the ST7565.
This controller needs the a0 pin since it looks like it uses it to select what the incoming spi data is doing: command or display data. An extra pin from the Duet Maestro would be required but I am unsure where it could be taken from, it doesn't look like here is an extra pins available on the lcd or SD car expansion headers. Perhaps a pin on the expansion header could be used.
I am planning on using this is for a Flashforge Creator Pro and the Viki2 is such a close fit size wise and I think it would a better match with the styling of the printer than the Paneldue.
I could certainly use a PanelDue 4.3 and I am using one on my RostockMax conversion and I have one on my kossel and really like it.
The display driver in the Display subsystem of RRF is for the ST7920 chip, not the ST7565. So if the Viki2 uses the ST7565, you would need to modify the driver for to work with it, as well as providing the additional data line - which you might also need to level shift from 3.3v to 5V.
I will take look and see if I can make the changes required and sumbit them back to the project.