LinuxCNC + Mesa 7i92TF + Gecko G540. Docs are useless. Help, Please!

Hello all. I have been trying to get this setup running forever. I'm embarrassed so say how many hours I've spent googling, typing in terminal commands, letting Chatgpt hallucinate answers, and reading 'official' web pages. The official page for PnCConf shows me completely different screens than the ones I see, with the latest version installed. 

Is ANYONE using this configuration? If not, what would you recommend that actually works? I went from Mach3 on an ancient XP machine with a DB25 serial port. I was told this would be the upgrade solution that just works. It's done anything but. 

I have the proper firmware flashed to the 7i92TF for the G540. The computer is able to ping the Mesa card. 

I cannot figure out how to configure PnCConf for this setup. I cannot find any directions that show me the screens I actually see. 

Any help would be immensely appreciated. I am ready to give up and walk away from 2 years worth of design work done during the pandemic, because I cannot get some seemingly simple hardware to talk to each other. 

Scott Jennings
Route 66 Guitars 

Chat GPT is uesless for more things Linuxcnc related.

Googling "linuxcnc 7i92 g540" (the TF denotes a different fpga but it functions the same)gets me this (possibly the most in depth one, I dont think too much has changed in pncconf since 2023):
forum.linuxcnc.org/49-basic-configuratio...and-g540-combination

This one has some simple hal files to look at:
forum.linuxcnc.org/49-basic-configuratio...indle-encoder-issues

forum.linuxcnc.org/39-pncconf/29692-can-...re-mesa-7i92?start=0

Some of them are a little old, hopefully PCW will chime in with some up to date info.
I think the first link has some screenshots of PncConf.

I would just use pncconf to setup a G540 configuration (config page): 

 

And the setup the pins on the P2 tab: 

 


The main thing that's awkward is the mapping of GPIO pins for things like  limit/home switches

and spindle-on, but you can list the GPIO/G540 correspondence with mesaflash:
something like:

mesaflash --device 7I92T --addr 10.10.10.10 --readhmid --dbname1 g540 

ChatGPT is just a time sink here

Does the specific firmware for the G540 for the 792TF need to be loaded on the card?

Just asking for a friend.

Yes, I have flashed the G540 firmware to the 7i92 card.

Thank you so much for pointing me in the right direction. 

Yes, any AI I asked eventually started hallucinating code that broke things. 

I did have someone send me a template HAL & INI set for the machine I am using (a Platform CNC with upgraded linear rails. Excellent hardware, currently being let down by confusing software, and its operator.) I was able to cobble something together that mostly worked, after much iteration. Since this was done manually, it didn't help me with learning and using PnCConf, which I would prefer. 

At this point I have everything moving, but until I sort out homing, the Y & Y2 axes are not moving in unison. They are seen as separate Joints 1 & 2. I assumed there would be some way to simply lock them together as one gantry joint(?), but apparently that's not how LinuxCNC works.

You can setup gantry machines with pncconf:

 

Thank you.

This essentially gives me the HAL I created by hand. This does not bind the two Y axis motors together. Launching LinuxCNC with this HAL still shows me the 4 joints, until I home the Y axis where it sits, which is not where I need it to be homed.

I pored over the HAL and INI files created by PnCConf using your settings multiple times, and cannot see what I am doing wrong. There seems to be no difference between what it generated by selecting Y2 Tandem StepGen, and my manual HAL where I simply copied the Y axis settings, pasted them in, and changed every instance of Y to Y2, and 01 to 02.

The machine does not currently have limit switches. I have the limit switches commented out.

I recently rebuilt the machine from the ground up. As the software is an upgrade, I am trying to get it working in its most basic form before adding limit switches, a touch plate, a probe, and a tool changer.

Do I have to have hardware limit switches set up in order to get the gantry to work correctly?

Apologies if that is a dumb question. I have found the documentation incredibly lacking, which is why I’m here on this forum.