Nintendo can't control anyone else's hardware, they can't stop you from doing what you want on a Raspberry Pi. They're trying to crack down on Switch modding, but even that's just a cat-and-mouse game.
You will not get in trouble for emulating at home. Emulation itself is legal, it's only illegal to download games you don't own. But it's nearly impossible for anyone to get caught doing that, and very obviously not worth any lawyer's time to pursue individual end users for pennies in damages. You are safe.
What Nintendo wants to do is attack piracy at the source. They can go after sites that distribute ROMs, but those are like a hydra, kill one and three more take its place. Then there's the likes of Yuzu and Ryujinx, where Nintendo claims to have found some technicality about these emulators having something they shouldn't. But the forks are still being distributed, and you the end user will not get in trouble for downloading the fork at home.
Note that for the most part, they're really only concerned with protecting their current hardware. They've never gone after Dolphin, Snes9x, mGBA, etc, because they know those are battles they can't win. Considering how aggressive Nintendo is on the battles they do fight, it's clear that anything Nintendo doesn't go after is something they can't go after.