Raspberry Pi 4 Tutorial - fatal error

Find older packages and use them. There are no older packages for RPi 4, but the packages for RPI 3 work. Get those for raspbian 9 and it should all work again.

I'm back on a decent computer and could look for it. Here is how I solved the python-rsvg missing package
forum.linuxcnc.org/18-computer/36879-ras...pi-4?start=50#140800

I assume that other old packages can be found at the same place.

I gave it a whirl and one thing that got me a little off-track was that I had gotten used to cutting and pasting the commands and it was late evening and when I got to this one "sudo apt install openbox, lxterminal and lightdm" it failed because I should have entered:

sudo apt install openbox
sudo apt install lxterminal
sudo apt install lightdm

I also lost my network connection (my fault) while debuild -uc -us was running and had to start it again.

Now, how do I start Linuxcnc from the command line? It is not on the Caja menus and I tried "linuxcnc" and I get "command not found". At this point I was just going to check latency as I don't have 7i76E yet.

JohnnyCNC wrote: I should have entered:

sudo apt install openbox
sudo apt install lxterminal
sudo apt install lightdm

This works too:

Now, how do I start Linuxcnc from the command line? It is not on the Caja menus and I tried "linuxcnc" and I get "command not found". At this point I was just going to check latency as I don't have 7i76E yet.

If it is a built-from-source run-in-place version then before you can enter any linuxcnc commands you need And that really is dot space dot slash.

If you followed the tutorial past the point of installing LinuxCNC you just open a terminal and type

I add them to the right click menu by opening a terminal and running the menu config tool
I'll work on the tutorial some more when I return from vacation.

Thanks for the feedback.

JT

I tried linuxcnc at the command line but got "command not found".

I'm going to try what Andy said and see what happens. I'm going to get a couple more SD cards so I can run through it again without wiping out this one.

Thanks

Did you install LinuxCNC?
gnipsel.com/linuxcnc/uspace/rpi4-emc.html

The next step after installing OpenBox is to install LinuxCNC...

JT

Yes, I did. But I just did everything on the Install LinuxCNC
page again and it is now working. I must admit that every time I read about someone wanting to use a RPi my thoughts when to "Do you want to build a CNC machine or play with a Pi?" I must say that so far I am impressed with how snappy LinuxCNC feels and how bright the display looks. I have a Pi 4 with 4mb. Now to run the latency test and see how that goes.

Thanks
John

I ran the latency test with 6 glxgears running but no other abuse.
Servo thread (1ms): 73079
Base thread (25us): 93953

If I run just the servo thread the number goes up over 100,000.

Anything I should try to lower the latency on the Pi4?

I may get a 7i76E and give this a try. Right now I'm using a 6i25+7i76+7i83

John

You could also use your 7I76 and 7I83 with a 7I92H or 7I92M replacing the 6I25