rtic/book/en/src/by-example/app_task.md

Defining tasks with #[task]

Tasks, defined with #[task], are the main mechanism of getting work done in RTIC.

Tasks can

• Be spawned (now or in the future, also by themselves)
• Receive messages (passing messages between tasks)
• Be prioritized, allowing preemptive multitasking
• Optionally bind to a hardware interrupt

RTIC makes a distinction between “software tasks” and “hardware tasks”.

Hardware tasks are tasks that are bound to a specific interrupt vector in the MCU while software tasks are not.

This means that if a hardware task is bound to, lets say, a UART RX interrupt, the task will be run every time that interrupt triggers, usually when a character is received.

Software tasks are explicitly spawned in a task, either immediately or using the Monotonic timer mechanism.

In the coming pages we will explore both tasks and the different options available.