Raspberry Pi 4 - USB not working under LinuxCNC

andypugh wrote:

_But_ there are Arm64 packages on Debian now...

But only for a week or so. I have not had time to test this on my Pi 4b but I think you should grab the Debian Bookworm image from here
raspi.debian.net/daily-images/
And install with the normal Raspberry installer

This will just give you a command line interface so run
sudo tasksel to install a windowing system of your choice

Then just type
sudo apt install  linuxcnc-uspace linuxcnc-uspace-dev
to install linuxcnc.

Please let us know how it goes
Note you will end up with V2.9

Hello guys,
first, I am super impressed with your quick and direct support, esp. since I recognize your names from a lot of other posts. That is great and I want to say thank you!

In the next days I will give your suggestions a try i.e., 3GB limit, kernel swap, different image, maybe recompile LinuxCNC - probably in that order. I will keep you/this forum posted about my results and hopefully a working solution.

I am very interested in getting a RasPi solution running, in combination with my Mesa 7I92H cards. I want to use such a low cost solution, still at high performance due to closed loop servo drives, ridgid tapping etc., for small formfactor CNC mills/lathes. Further motivation - I want to replace my annyoing NCCad/kosy CNC controller (from MaxComputer), at use with a Wabeco CNC mill. In another forum one member said, that this SW/HW platform has more bugs than features. In short, it is quite painful to use and yes, the bug level is pretty high.

Greetings

Stefan

Ok, I followed the "3GB limit" recommendation, as discussed here: forum.linuxcnc.org/9-installing-linuxcnc...i-4-8gb-2gb?start=20 . It worked! In my case, the Chromium web browser still works - in the link above it was reported to fail.

Approach: I modified the /boot/config.txt. First, I opened the LXTerminal window and entered "sudo nano /boot/config.txt" to edit the file. Then I added "total_mem=3072" under the "[pi4]" section. Then I rebooted.

To do that you need to terminal into your RasPi from another computer, since USB mouse and keyboard don't work.

Stefan

Hello Andy,

despite the 3GB memory limit workaround, I am very interested in a "how to" compile LinuxCNC from source. You mentioned it isn't particularly difficult and I would like to dive into this topic with the target RasPi in mind. Therefore, any help or pointers into this subject are apreciated, like a simple (less workload for the authour/writer) step by step approach, incl. pointers to where I can find "THE" LinuxCNC source files (GitHub?) and maby how to createt the build with corresponding "make" settings. All with RasPi 4B in mind.

PS: I am into programming embedded systems (ATMEL chips), and Windows systems, using C/C++, thus my interest. Now, I would like to get my feet wet in the Linux/Unix world.

Thanks
Stefan

Hello rodw,

thanks for your input.

In case that you are interested in my results using the link you provided =>

I tried the Debian 12 Testing (Bookworm) package, from your link, on a 64GB SD card without any special pre-formattíng of the card, using the Rasberry Pi Imager program. After SD card was flashed/veryfied I got follwing error message:
"Unable to customize. File 'K:/config.txt' does not exist".

Regardless, I tried to boot the RasPi from that the SD card and the boot failed with following message:
"Boot failed: Unable to read partition as FAT"

I tried to partition the SD card (under Windows 10) and setting it up with a 32GB volume. That didn't work either, using again the imager. Same error message.

When I use RasPi images, i don't have such problems with the same 64GB SD card.

Greetings

Stefan

I spent all day today playing with a Raspberry Pi  to see if I could install from the new package in debian testing.
I was able to install from the Debian images
It proved to be very unreliable and hung repeatably no matter what I did.
The problem I had is there was no preempt_rt patch for 5.15 and I did not know how to install the preempt_rt patch which on amd64, is installed with linuxcnc.
 
In the end, I installed from the complete image on this post as they had a preempt_rt 5.15 kernel
forum.linuxcnc.org/9-installing-linuxcnc...cnc?start=130#238020
Which worked perfectly with very low latency. 

I then uninstalled linuxcnc and attempted to install it again from the testing (aka bookworm) branch which is ahead of the stable (aka bullseye) branch. we are using here This seemed to work ok but when I tried to open qtplasmac, it failed looking for python-gst1.0 and I was unable to resolve the error.

So I think the way forward to get an updated version of linuxcnc master branch  is to use the forum post and  compile from source and install the deb files.

This is quite easy and I have a screen share of how to do it  here