stm32f103xx-hal

If you want to get something done with microcontrollers, ARM Cortex-M tends to be much more powerful and is already great fun to write Rust for. It's a bit of work to get started--certainly a lot compared to Arduino which abstracts away even things that shouldn't be--but the code can be much more readable and portable than the corresponding C. For example, get this $2 board http://wiki.stm32duino.com/index.php?title=Blue_Pill and use this library (see the examples!) https://github.com/japaric/stm32f103xx-hal There probably will eventually be AVR implementations of https://github.com/japaric/embedded-hal so you could run mostly the same code on an Arduino board.

Having Rust support embedded is only half the story: we need to lobby/advocate for chip makers to support Rust. The article doesn't directly call this out, but I think it's important for Rust to truly succeed in this space. Most embedded systems are fairly closed ecosystems built on vendor-specific stacks, and most professional embedded engineers wouldn't want to use Rust until the vendors support it. This isn't to say the hobby world (ala Arduino/Raspberry Pi) wouldn't benefit from Rust, but I think the long-term viability depends on the ARMs, STs, TIs and Renesas' of the world starting to embrace Rust. To date I haven't seen this happen (although I'd love to be proven wrong!) Edit: just noticed the recommendation to use a Blue Pill for Rust dev. They're cheap on eBay (just picked up 2 a few days ago) https://www.ebay.com/itm/STM32F103C8