Async Rust vs RTOS showdown!
It's time for another technical blog post about async Rust on embedded. This time we're going to pitch Embassy/Rust against FreeRTOS/C on an STM32F446 microcontroller.
They will both be running applications that perform the same actions. We're then going to judge them on the basis of interrupt latency, program size, ram usage and ease of programming. There are already a lot of articles that compare C and Rust, so we're not going to focus on that today.
What I will try to show are two 'normal' applications. Both projects could be tuned to give better performance with a lot of work. Doing that can be a nearly endless task. So as a guideline, the applications will be:
We'll be testing with the STM32F446ZET6 microcontroller at 180Mhz and some of the measurements will be done with a Rigol DS1054Z oscilloscope.
The function is transformed into a state machine object that can be polled. The state machine allows the code to jump into the function, resuming where it previously stopped. It also keeps track of all the variables that are retained across await points.
