Raspberry Pi 4 with Mesa 7c81

When you run pncconf, you choose the machine name.
When you have finished creating a configuration, the hal/ini files
will be stored in your home directory/linuxcnc/configs/machine_name/.
The ini and main hal files will be named "machine_name.ini and
machine_name. hal.

For example, I just ran a pncconf session and created
a configuration for a machine called "bob-jones", here
are the files in the created directory:

peter@pcw-HP-EliteDesk-800-G1-USDT:~/linuxcnc/configs/bob-jones$ ls
backups custom_gvcp.hal postgui_call_list.hal
bob-jones.hal custom.hal shutdown.hal
bob-jones.ini custom_postgui.hal tool.tbl

The card name is in the bob-jones.ini file:

[HMOT]
CARD0=hm2_5i25.0

You would need to change this to

[HMOT]
CARD0=hm2_7c81.0

The driver is specified in the bob-jones.hal file:

loadrt hm2_pci config=" num_encoders=0 num_pwmgens=1 num_stepgens=5"

You would need to change this to

loadrt hm2_rpspi config=" num_encoders=0 num_pwmgens=1 num_stepgens=5"

BTW the main card setup I used was:

config (note that I have chosen 5 stepgens since 1 is used to drive the G540s charge-pump)



connector 3 (which would be P1 on a 7C81)

Thank you so much. I have made the changes. Last question... is it necessary to change all instances of 5l25 in these files to 7c81 or just the two instances that you mentioned?

There should only be one instance of "5i25" and it should be in the .ini file.

This is using the latest version of pncconf and there is a feature for having the
card name as a substitution (alias) from the .ini file:

Reading through the Hal file there were several instances. Ex:

setp hm2_5i25.0.Stephen.04.dirsetup

I did not check the use ini substitution box in pncconf. Should I go back through and do that?

Or alternatively make all the changes in the Hal and ini files?

Thank you. This has been such a process and learning experience. Can’t wait to finally turn on the machine!

*correction. Example should have read

setp hm2_5i25.0.stepgen.04.dirsetup

You can do it either way, I prefer the substitution way
rather than doing a global find/replace

Huge thank you to PCW and andypugh! I have a functional cnc router! So grateful for the knowledge, quick responses and this forum.

Back in this forum with an unusual issue that has me puzzled...

There is an issue with my router and circular cutting. When cutting arcs the machine is adding a small linear cut somewhere mid arc (see attached photos) In the photo marked A you can see that it was cutting a very nice arc then all of a sudden moves in a direction that is not part of the arc! I wrote very simple gcode program to test the arc in the part of the photo labeled A in an effort to eliminate the problem being a kCAD/CAM issue as this problem was originally discovered cutting an ellipse using CAD/CAM (label B in photo).

The axis are moving in the same direction throughout the arc which has eliminated backlash as the culprit.

Additionally I have been V carving with the machine and the results have been perfect (including curves of letters, picture shapes etc.)

This seems to be a problem with simple arcs

Totally stumped. Not sure if it’s settings or an issue with the 7c81. Any help would be greatly appreciated.

Is this repeatable?

Is position lost when this happens?