g76 code or g33

I am confused by the lack of "loadrt hostmot2" and "loadrt hm2_pci..." but I assume they are in a separate HAL file?
Also, there is no need to addf the 5i20 read_gpio and write_gpio threads, in fact you shouldn't do that unless you have a fast thread and need to write them in that. (your current HAL file is writing the GPIO twice, as the plain ...read and ..write also read/write the GPIO)

You don't have anything connected, in that HAL file, to motion.spindle-at-speed, so AFAIK threading etc should just happen.

nkp wrote:

are there any plans of developers
thread cutting with variable pitch in Linuxcnc (G76)

I don't know, but I doubt it.

It would be wrong to imagine that there is a master-plan for LinuxCNC, or even a list of planned new features. Things tend to happen only when someone wants them.

Why do you want variable-pitch?

You may be able to do what you want inside the existing capability:

(There is a link to further details of how it was done)

nkp wrote:

master-plan for LinuxCNC
I would very much like to do - but I do not know C

That's no excuse, I had never used C (or any programming language other than VBA) when I decided to add support for the three-phase PWMs in Hostmot2.

Anyway, will jmk's approach to variable-pitch threading work for you?