araffin:
Looking at your code, it seems that you are trying to solve a different problem that is sending strings.
I find that sending data in human readable form makes debugging very much easier and I always use it unless I need the extra performance of sending binary data - which is very very seldom.
I have had a look at your main link GitHub - araffin/arduino-robust-serial: A simple and robust serial communication protocol. It was designed for Arduino but can be used for other purposes (e.g. bluetooth, sockets). Implementation in C Arduino, C++, Python and Rust. and I find myself more confused than I was before.
I had assumed there would be a .ino file representing the Arduino code and (for example) a .py file representing the Python code.
There is a list of functions on the main link - for example read_i8(). Is that an Arduino function or a Python function, or both?
...R