PID feedback derivative

Hello,

I would like to sample the pin pid.N.feedback-deriv, but it is an input pin. Is there a way to do it?

Also, from the PID page: "If no signal is connected then the derivative will be estimated numerically". Where can I access this information? Is there a way to change/copy its value to an output pin?

Thank you.

You should be able to get the same numerical value by using the "ddt" hal component on the feedback value.

github.com/LinuxCNC/linuxcnc/blob/master...omponents/pid.c#L376