A simple example demonstrating how to add an at-time worker to an async_context.
The program creates an async_context_threadsafe_background and uses an at-time worker to flash the LED on a Pico or Pico-W board.
An async_context_threadsafe_background is generally used to ensure that a non-reentrant library such as lwIP can be used successfully in a multi tasking application; so a practical networking application would typically use the async_context provided by cyw43_arch rather than creating its own.
More details about async_context can be found under High Level APIs in the SDK documentation.