Addon PCB to give the original Craftbot the backup functionality of the Plus-Version. In order to make it work you need to solder two enameled wires to the atmel controller, one the VDDBU and one to corresponding GND. Furthermore you have to lift the VDDBU pin and thus disconnect it from the 3V3 supply, otherwise the battery will supply the complete chip and not only the low-power backup function (this will drain the battery in a couple of hours).

For further information refer to the craftunique forum, where you can find detailed photos and additional information. https://craftunique.com/forums/view-thread/2387/#20585

Infos for populating the pcb: D1 is a Bat54c double barrier diode, and the pcb supports two types of CR2032 holders, you also need two female pin headers (0,05" spacing) to connect it onto the controller pcb.

For the addon pinstrip: only VDDBU and GND are needed, you are not supposed to connect the 3V3 pin.