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Hello,

I have run into a need for LinuxCNC. I'm wondering if some kernel / device driver work is needed for supporting LinuxCNC on Pi 5. I would look for a user to be able to download, install and use the software without high-level technical support.

Please let me know your thoughts.

Thanks,
Tom Alborough
----
Some of my related work:

"Thomas Alborough Unix" - (Use citations that contain "Unix" and "Alborough")
"Thomas Alborough Guide to Writing a Unix Device Driver" - (Search for "Alborough")
LinkedIn... Search for "Thomas Alborough"

This is the download link

drive.google.com/file/d/1pmV587gXFEvznQB...00x/view?usp=sharing

Something has changed on linuxcnc between then and now, but not much.
In particular, the function for using GPIOs which was previously hal_pi_gpio and is now hal_gpio
linuxcnc.org/docs/devel/html/drivers/hal_gpio.html
forum.linuxcnc.org/24-hal-components/504...-with-raspberry-pi-4

The image of RaspiOS with Linuxcnc is available in this link

forum.linuxcnc.org/9-installing-linuxcnc...pi-5?start=40#303752

Let me know if you need further guidance

Use the one Rod linked to on his google drive as it handles screen resolutions much much better.

With Linuxcnc is somethings works generally users stick with it. There is still many machines running earlier versions of Linuxcnc on Ubuntu 10 series.

Think of a machine running Linuxcnc the same as an ECU on a pre 2000's car or bike, if it works don't mess with it..........unless you're racing

You can connect TTL level encoders directly to 7C81 I/O pins
_but_ I would at the minimum add say 220 Ohm resistors in series
with each signal to protect the inputs from negative input spikes.
(encoder signals tend to pick up motor drive noise so are fairly hard
on unprotected inputs)

I'll answer with experience of using Aliexpress Omron type encoders www.aliexpress.com/w/wholesale-omron-rotary-encoder.html , which are about less than a tenth of the price of the ones you mentioned, it's nice if you mention parts you can provide a link, saves time trying to search and ensures the correct component is being discussed.

With an optocoupler you will need to ensure the optocoupler is fast enough and the encoder can drive the optocoupler's led hard enough.

If the encoder is true TTL output or open collector output it should be fine.

Personally I've just used simple buffers, 74hc540/541, as I have a couple of tubes of them.

Another option would be to use the differential output of the encoder and connect that to a differential line receiver, such as www.futurlec.com/Linear/26LS32pr.shtml.

The schematics for the 7c81 are available, forum.linuxcnc.org/media/kunena/attachments/481/7c81sch.zip , one of the sheets shows the input circuitry.

No doubt Pete from Mesa will chime in.

Hello

I have a question about connecting the encoders in the set:

RPI4 + 7C81 + Mach5 3-axis board.

Since the 7c81 documentation says about a 5V tolerance (inputs), can I connect the encoders directly to the 7c81, or is it better to protect them with an optocoupler?

Will the encoders:
ROD426
ROD420
be suitable?

Thanks in regards, 
Michal

After six weeks of doing everything wrong a few times and being graciously corrected by everyone in the community my franken-build Pi 5 debian is working very well.

I'm about to start clean and do everything as has been documented in this thread without my own improvisations which I think got me little except the motivation to learn everything necessary to fix all the things I broke.

I wanted to make sure I'm starting with the latest of Rod's builds and I think it is this from the Google-Driver:

   rpi-5-debian-bookworm-6.6.54-rt39-arm64-ext4-2024-11-06-2037_qtpyvcp_stable_networkmanager.img.xz

The one on the Downloads page is still:

   rpi-5-debian-bookworm-6.1.61-rt15-arm64-ext4-2023-11-17-1520.img.xz

I'm pretty sure I want the one from Nov 2024 instead of Nov 2023.

Is there an even newer one?


 

WooHoo - It started right up!

Thanks a bunch.

Victory! (of step 1, now I move on to step 2, building my HAL  )

I am using the Raspi build (forum.linuxcnc.org/9-installing-linuxcnc...erry-pi-4b-5?start=0), but after recompiling mesaflash from git it worked flawlessly!

Thank you so much for guiding me along!

Thanks again, professor. have you had the opportunity to look for the digital copy of the thesis?
If I'll need some help I'll reach out to them. If we wont hear any time soon i wish you a happy new year.

The professors who know me and I think deal with these issues are at DIMEG.

You can go to them saying I was the one who reported them and ask

infodimeg.unical.it/associate_professor/card/152

infodimeg.unical.it/associate_professor/card/148

try
DISPLAY = qtvcp qtdragon

Hello, it's been a while... i hope you had a merry Christmas. It sounds awesome to me. But i think it will take a while because i am preparing my last exams. Maybe there's a chance i may already know the UniCal professor you're talking about, if he's in my department (DIMES).

Hope to hear you soon. Sorry for the day in my reply, but I'm studying and working too.
Thank you so much

I've had good luck getting everything to run well enough to get deep into learning and configuring LinuxCNC, Mesa 7i95T and the needed .ini and HAL files.  However, I just ran into my first problem when LinuxCNC errors on start when I configure QtDragon as the interfaces. 

I've already worked my way through several prior fail-on-start situations chasing down reported errors from the usual sources but this one is stumping me because I can't seem to find the actual error in the outputs I'm aware of.I will attach everything I can think of if someone could take a peak and spot what I'm missing.

Thanks

Stop overthinking.
With mesa hardware you don't need a base thread, only a servo thread is required. With that, latency isn't such a huge issue either. Trying to get an extra bit here and there does nothing.
The pre made image Rodw recently linked to is perfectly fine to run a machine, the only exception would be if you are using the RPi 5 spi interface to talk to a 7c81 or 7c80 as this requires a driver that isn't included in Rods image , this is not required for ethernet.
Invest more into learning the ins and outs of hal . This is more important that fussing over software as the images provide what is required, remember the only task these images are meant for is running a CNC machine.
If one reads the online docs one will fine some simple exercises that do not require a CNC machine.