Hal Standalone. some trouble..

Do you have any suggestion on how to make stepgen decelerate if, in position mode, I have to stop in the middle of a movement?

Would simple_tp be helpful?
linuxcnc.org/docs/2.8/html/man/man9/simple_tp.9.html
It's a single joint jogging component - same as linuxcnc uses.

You could also look at the axis test used in stepconf.
Though I think it stops immediately if you stop in the middle of a jog.

Chris