Files inside 3d_models
folder must be copied into <kicad dir>\share\kicad\modules\packages3d
Arduino Nano library downloaded from http://sylvain.fish.free.fr/kicad_lib/
NRF24L01 library downloaded from https://github.com/mysensors-kicad/mysensors_symbols
NRF24L01 footprint downloaded from https://github.com/mysensors-kicad/mysensors_radios.pretty
NRF24L01 3d model downloaded from https://github.com/mysensors-kicad/mysensors.3dshapes