Stepper Motor Start and Stop Pulse Profile[SOLVED]

[Ttelmah]

Still the call to the interrupt needs to be much faster.

The problem is that this has to be at a significant 'multiple' of the actual stepper speed required.
Otherwise the gaps between steps gets enormous.

Visualise that the step rate required 'is' the interrupt interval.
Then the interrupt can only develop pulses at this frequency, or half this frequency, 1/3rd this frequency etc.. Result very non linear, and big jumps in speed.
If instead the interval is 20* the maximum rate required, then the timer can generate this frequency, using /20, or /21, /22, etc., and there are small changes between the rates, and acceleration/deceleration is in small steps. This is why I talk about such a fast interrupt.
This approach _relies_ on having the master interrupt at a fast rate.