Thanks PaulS
How do I do to attach an .INO file at this moment? The sketch is too large to be put into Code tags.
The case 'C' and Serial.print was an accidental Ctrl V at some time and it is corrected now. It doesn't change anything
Making a stepper motor of 400 steps per millimeter move some 200 mm needs 400*200 == 80 000 steps. A little too much for Integers....
The two ways of sending the string are X123 Carriage Return, or X Carriage Return, 123 Carriage return. The first way works, the second onle gives the value 1.
Isn't The Cr dropped in Serial.read, treated as a delimiter?
I'll try to create a test sketch later today. Cutting away code without loosing neccessary lines is never an easy task