HI.
Loaded Android to emmc using usb A-A Cable & RKdevTool.
Usb A-A Cable to USB3 port
Put nanoPi device into Img mode (MASK button depressed whilst connecting power, release mask button after 4-5 seconds
Start RKDevTool_Release_v2.84
Change all .bin files to point to extracted Android image folder equivalents
Then Click Highlighted first button (next to words Loader Ver 1.ob) to write image to eMMC
Hope that helps.
Drew