I2C, RX/TX, SCK,MISO,MOSI - map 1:1, but to where connect SPI select on feather? or have lots of solder jumpers?

This adapter if done "full passive" would be really easy to-do, and it would allow also some very nice things when used with Greg's coming ECP5 feather!

Actually the HS connector could also be fitted, but then a bit more issues (open questions) arise so maybe this passive adapter is good for the first Feather adapter.

Q: what todo with unused feather IO ? and unused PCB space? some proto area?

Greg added this high speed connector to his Feather, but I dont know if it would be possible to wire it up to the adapter.

https://twitter.com/GregDavill/status/115180597056299417670562994176

its on the bottom :)

https://www.digikey.com.au/product-detail/en/hirose-electric-co-ltd/DF12-30DS-0.5V-86/H5215CT-ND/948728

well, gregs feather could be converted to cruvi using this connector.. its the other way around.. hmm
or then small mother board with gregs slot + cruvi slot, that would do also