This is a board configuration for using mainline micropython with the UBLOX EVK-NINA-B3 board for use with mainline Micropython
Just copy the evk_nina_b3 folder to <your-micropython-folder>/ports/nrf/boards and follow the same instructions for compiling any other nrf board, just setting the BOARD variable to _"evk_nina_b3".
Examples:
make BOARD=evk_nina_b3
make BOARD=evk_nina_b3 deploy
make BOARD=evk_nina_b3 SD=s140
make BOARD=evk_nina_b3 SD=s140 sd