engraving depth setting in realtime

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

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 ?

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

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?