One of my "wishlist items" for vintage computing is to have an open LocalTalk/EtherTalk bridge project. Unfortunately I don't have time to work on it myself at the moment but there is some movement worth documenting so someone else can start work on it or I might be able to find it again when it gets higher on my project priority list...
Theoretically you could probably do this all with a microcontroller with an Ethernet interface and skip the Pi. My thought is that it's almost certainly faster to debug and prototype it with a Pi. It would also allow you to conveniently build a netatalk fileserver and MacIP gateway into the same device.
- tashtari on 68kMLA has created an open LocalTalk transceiver using a PIC called TashTalk. See 68kMLA and Github
- sfiera on Github has code that can bridge EtherTalk and LToUDP. See Github
Theoretically you could probably do this all with a microcontroller with an Ethernet interface and skip the Pi. My thought is that it's almost certainly faster to debug and prototype it with a Pi. It would also allow you to conveniently build a netatalk fileserver and MacIP gateway into the same device.