Migrating to rtic-monotonics

In previous versions of rtic, monotonics were an integral, tightly coupled part of the #[rtic::app]. In this new version, rtic-monotonics provides them in a more decoupled way.

The #[monotonic] attribute is no longer used. Instead, you use a create_X_token from rtic-monotonics. An invocation of this macro returns an interrupt registration token, which can be used to construct an instance of your desired monotonic.

spawn_after and spawn_at are no longer available. Instead, you use the async functions delay and delay_until provided by implementations of the rtic_time::Monotonic trait, available through rtic-monotonics.

Check out the code example for an overview of the required changes.

For more information on current monotonic implementations, see the rtic-monotonics documentation, and the examples.