the new mk logic and driver boards are compatible with older 40h keypad kits. however, if you're using multiple 40h keypad kits tiled together into a larger grid, you'll have to rotate the boards in order to maintain proper keypad spacing:
keep all connectors on the outside of the grid (same applies to a 16×16).
the mk driver is connected as shown below:
we've written a alternate version of the firmware which performs all of the necessary software rotations so that your rotated boards will work correctly. these firmwares are preceded with alt in their titles, for example alt-encoders.
new logic boards ship standard with the encoders firmware, so if you're using 40h keypad kits, you'll need to flash your firmware with alt-encoders. see this tutorial on firmware flashing for further instructions.