I recently set out to use one of the cheap “blue pill” STM32 ARM ... see that your program gets added to other things and put in a directory named something like /tmp/arduino_build_XXXXXX ...

It just runs your program, what the Arduino folks call a sketch (and the rest of us would call a script). You can pick up an Arduino Uno for as little as 25 bucks, but I'm going to recommend you ...