engraving depth setting in realtime

wicki wrote: The number of pins, signals and functions is really overwhelming.....

It's a feature, we call it "Flexibility". There really is very little that you can't do in HAL.

This HAL file here uses it: electronicsam.com/images/emco/linuxcnc_c...Morph/emco-lathe.hal

andypugh wrote:

wicki wrote: The number of pins, signals and functions is really overwhelming.....

It's a feature, we call it "Flexibility". There really is very little that you can't do in HAL.

Oh, yes - there is also a human feature called language - it is also very flexible.
But it took several years to use it

Thanks for all the hints.

With the collected information I now wrote this:
(and it seems to do what I want)

---

addf Z.update-output servo-thread
addf Z.update-feedback servo-thread
net zpos-cmd => Z.in
net zpos-fb => Z.fb-in
net zpos-cmd-corr Z.out
net zpos-fb-corr Z.fb-out
net zpos-offset Z.offset
unlinkp stepgen.2.position-cmd
unlinkp axis.2.motor-pos-fb
net zpos-cmd-corr => stepgen.2.position-cmd
net zpos-fb-corr => axis.2.motor-pos-fb

---

In the next step I will try to use this in a shell-script:

halcmd sets zpos-offset $offset

wicki wrote:

andypugh wrote: In the next step I will try to use this in a shell-script:

halcmd sets zpos-offset $offset

It would also be quite easy to connect it to a physical knob. I din't know if that would help.

The china-caliper-solution is off the table now: to big and to sensitive.

Now I read a forked light barrier with a microcontroller. It delivers several 100 steps
on distance of 1/10mm.
The values are read via ttyUSB as ASCII numbers.
In a first test with an awk-script, it holds the Z-axis in place with a difference
from about two 1/100 mm.

Instead of an own script, which uses hacmd to move the Z-axis - is there an (easy)
way to read ttyUSB via HAL ?

Possibly with hal_input

www.linuxcnc.org/docs/html/man/man1/hal_input.1.html

hmm.... sounds nice

but the PL2303 is not listed in
cat /proc/bus/input/devices

in lsusb its listed and I can read from it.

Bus 001 Device 009: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

You might be able to create a userspace Python HAL component that can read the data.

Does it show up in cat /proc/ioports ? If so then a realtime hal module might be able to get the data with rtapi_inb()
www.linuxcnc.org/docs/html/man/man3/rtapi_inb.3rtapi.html

andypugh wrote: Does it show up in cat /proc/ioports ? If so then a realtime hal module might be able to get the data with rtapi_inb()

no, this is not a real serial interface. Its a usb-serial-converter.

Is it possible to let HAL read from a file, device or from shared-mem directly?
or is it necessary to create a component for this?

You need a simple component to put the data in shared-memory.

www.linuxcnc.org/docs/html/hal/halmodule.html

I just remembered that there are already HAL comps that do serial transfers to USB-serial devices.

Parts of this code might be useful to you:
github.com/LinuxCNC/linuxcnc/blob/master...anyang-vfd/hy_comm.c

Most of that file if huanyang-vfd specific.