It's really not so different! In embassy, DMA transfers and interrupts become things that you can .await on, the process is basically:
* The software starts a transaction, or triggers some event (like putting data in the fifo)
* The software task yields
* When the "fifo empty" interrupt or "dma transfer done interrupt" occurs, it wakes the task to resume
* the software task checks if it is done, and either reloads/restarts if there's more to do, or returns "done"
It's really not different than event driven state machines you would have written before, it's just "in-band" of the language now, and async/await gives you syntax to do it.Even if you don't know Rust, I'd suggest poking around at some of the examples here:
https://github.com/embassy-rs/embassy/tree/main/examples
And if you want, look into the code behind it.
Precisely, I would say embassy is a satisfying middle-point between "baremetal" firmware and running something like FreeRTOS / NuttX that hides the event loop from you.