How to write HAL logic with Motion and Offset pin?

Hi everyone, I’m planning to make my standard 4-axis（X Y Z A） workstation cut a series of lines(curves) according to my inputs. The non-trivial part of my goal is that while cutting curves in the X-Y plane I need to use a visual sensor to control the Z axis in real-time. The work-flow(path) of my end tool will be: go to the start point of the first curve in an open space, start spinning the blade(always tangent to the cutting point) , go down until visual sensor feedback says ok, follow the first curve (while my visual sensor adjust the height of the tool in real-time) to the last point, then cut the next curve the same way and so forth.

The control board I’m using is a BeagleBone-black with Cramps 2.2. There is a config file available from Machinekit(see attachment). And I’m instructed to use HAL pins (motion and offset in particular to achieve my goal.

Here is the plan I came up with: Design a HAL logic which includes motion pins (to parse the cutting movement) and offset pins( to control the Z axis), integrate the HAL logic into a python script, say main.py, that imports linuxcnc( and may use pygtk). ( The main.py will receive the cutting-curves in the machine coordinate system from ROS (robotics operating system) topics, either in the form of a series of sets of coordinates or an depth image, I can do this part myself.) After receiving the cutting-curve, the Linuxcnc will start generating G-codes, and start cutting the curves in the way I described above.

Unfortunately I find it hard to write the HAL logic and integrate everything to my main.py ( I have 0 experience with linuxcnc and HAL, I’m looking for someone who find this easy please help me with some sample scripts or help me to write the frame of my main.py (without the ROS part) .

I’m really grateful for your time and help, and I’m willing to pay some cash for your help.
Please leave a message if you would like to do me a favor.

Hi Tommy, I found the plasma THC config, but my linuxcnc does not run with it, it reports an config error, axis not found etc.
I attached the config files from linuxcnc.
maybe I need to fully understand everything and make some neccesary changes before I can make use of it.

Hi, Tommy, Do you know how I can generate Gcode from a series of coords or a depth image from a python script?
I have a python script that stores a series of coords/ a depth image, I want to generate Gcode acoording to my coords/depth image, and make LNC start working with my coords.

Thanks for the config instructions =)
I'm planning to use image2gcode or dmap2gcode, but I'm not clear how to use them.
In my plan,
I will import linuxcnc in a python script,
and generate G codes from a series of coordinates or from a depth image within the script,
then I start running G-codes while using linuxcnc.stat().poll() to read the starts and use linuxcnc.command to control the motion mode.

but from the python interface documentation page I didn't find a command like dmap2gcode. so, I don't know how to generate Gcodes from an image or from a series of coords in a python script and start running the G-codes.

Hey Tom, I spent quite some time to try linuxcnc, i think it's really useful,
the hardware I'm using changed to a desktop with ASUS Z170-AR board and an iI6700K CPU, I bought a PCIe to Parallel and a PCI to Parallel card(MOS 9865) , the stepper controller board is a TB6560 board (AL-ZARD)
however Im having another problem, I failed to make ROS and Linuxcnc run together.

<edit> problem being solved, hhaha, i was building a wrong ros version with debian wheezy;


I tried to install ROS in a Debian system (Debian Jessie and Debian Wheezy, and Ubuntu Precise ) with linuxcnc already installed, I failed, because " the system holds broken packages ,,, can not install package xxx etc"
I tried to install Linuxcnc alongside with ROS in a Ubuntu system (ubuntu 14.04 trusty, ROS already installed) , I succeeded installing Linuxcnc and I was able to start it, but it can't be run in a non-simmulation mode (some errors such as command timeout and configuration errors occured that stopped linuxcnc; however I was able to run non-sim mode with the same configuration in Debian systems with the same desktop).
I tried to change my ubuntu 14.04 's kernel to RTAI kernel, but the system didn't boot properly, an error says INIT file not found.

Could you tell me how to make ROS and Linuxcnc run together?

The machine I'm building is to cut fur coats etcs. not skinning cats btw.
The gears haven't been installed properly, what I have is only a frame right now. see my picture.

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