This has been an interesting thread to watch, first rate work!

 

OK, but is it reasonably similar? ie command 22, motor ramps up to 22-ish? In your example, you've commanded speed=18 and the motor is running at 19, that's a correlation in my book. Is it true for all speeds commanded?

You're totally right. The bytes are very correlated even though they look different. And yes, it's true for all TX speed values.
With my software engineering background I'm always looking for a specific input to make a decision, but in electronics there is always a range of possible values.
I'm slowly learning but I'll get there one day.

 

With my software engoineering background I'm always looking for a specific input to make a decision, but in electronics there is always a range of possible values

Well yes, but electronic hardware is closer to the real world... as a software and hardware engineer the trick is to get the most accurate info from the electronics commensurate with the problem and then massage it with software. The real world is always fuzzy, there's always noise in the system. Real-world software has to accomodate that.