The Drogue IoT project is probably the best set of projects which enable building IoT devices in Rust. https://github.com/drogue-iot
It’s built on top of the Embassy embedded async runtime (which is great), and implements a lot of the stuff you need for IoT.
Unfortunately it seems to have been mainly written by red hat engineers who’ve been redeployed, so apart from a few active subprojects it’s mostly abandoned and slowly bit rotting. It’s a shame as it has real potential but didn’t quite reach production ready state.