Manual tool change + tool lengh touch off

I am afraid I am completely out my depth here, as I have never done any probing.

I might get the chance to experiment later, but I have a lot of other things to do.

It is probably worth taking this query to the emc2 mailing list, as developer coverage is better there.

From the docs it really does look like you should be able to do a fast G38.2 onto the switch and then a slow g38.5 off of it. If that is not working then I suspect there might be a bug that needs squashing.

It could be electrical noise. Exactly how is the switch wired, and to what?

What does the probe signal look like in Halscope?
If you are in the axis UI then it is Machine -> Halscope.

You could probably remove the lowpass and use the "debounce" function in HAL.
www.linuxcnc.org/docview/html//man/man9/debounce.9.html

I think that probe moves towards the indicated position. You might need a G53 on the same line as the probe command.

debounce needs to be added to the hal file. The process is much the same for any HAL component.

1) load the component:This loads a 1 channel debounce called debounce.0

2) Make the debounce function run in the base thread:
3) set the debounce time:
4) put the debounce between the parport and the probe input