From chatgpt:

```
Suppose you want to wake a future when data is available. You can:

Store a Waker in a static/global variable (with Mutex/CriticalSection).
In your interrupt handler, call waker.wake() when the event occurs.
In your future, register the waker on each poll.
But this is not idiomatic RTIC. RTIC prefers event-driven, non-async code, or you use an async runtime like Embassy.
```

The fact RTIC tasks are async fns puzzles me.