I feel like it's a poor starting point, too. embedded-hal or embassy would be a much better starting point. Ultimately if you know enough to know what a memory mapped register is, you can _probably_ become dangerous with Rust really quickly. The alternative is someone using Arduino libraries, who would greatly benefit from a HAL of some kind.

What I found is that the Rust HALs are incredibly thin and understandable, I was digging into MCU datasheets within a month of first using embassy (with no prior embedded experience).