(superseeded) Linuxcnc on Linux Mint 19.3 quick and easy installation

FWIW in my experience, anything Wifi has affected jitter in quite a bad way.
I got acceptable jitter with a laptop by making sure it's wifi switch was permanently left off and on a desktop box reduced jitter significantly by disabling wifi right from the get go in bios. An improvement from nearly 90,000 down to 15,000.
What I am saying is that when you boot into Linux for the purposes of using Linuxcnc, you may not want wifi active anyway.
To be clear, my experiences are with internal (mboard) mounted wifi, the usb mounted wifi you are trying to get going may be a different proposition.

rod i probably will not mess with it tonight any more but will get back on this for sure. i did not get any documentation on the USB WiFi it was just shipped in pink static discharge bag with the computer when i bought this refurbished Dell. it was not working on the Linux mint so i did not even get the plug and play from the beginning. i tried checking the driver but could not get through it since it was trying to connect to a network which obviously was not going to happen with the issue i am having i will see what i can dig up when i have some extra time. i will have to check your link out some more as well when time permits.not sure if it will show up or not on linux ? but i can at least get the manufacture from windows and let you know that much sometime soon. right now it's nap time i spent to much time today playing around still have one more night of work before i get some free time to get something productive done on all this stuff.

I never used wifi on a cnc pc in the past so if it is problematic it can be left out completely if need be. Only reason i was messing with it was because i use fusion 360 and it is cloud based. But i can just use my laptop for that and keep things separated which is probably better anyways. So your probably right especially since this pc has a parallel port. And if it gets used Wifi will cause problems there.

i played around a little longer with this. what i think is going on is the driver for the USB WiFi is not installed. the USB is from Realteck semiconductor corp. and the chip set is 0bda : c811

i did come across some info on USB WiFi and Linux and this one does seem to work with Linux but i would need to install the driver first.

i looked in the device manager and nothing is listed there so this would probably have to be done some other way?

the only way to connect to the internet is over a wired connection as of now. and the only network with a driver is the wired one.

I thought that the PREEMPT RT kernel patch was specifically written to overcome the problem of maintaining real time within a specific process and preempting any interruption of that process by other system tasks such as WiFi. It would seem to me that WiFi should not have an effect on LinuxCNC and, if it does, perhaps there's a way to use WiFi but specifically preventing LinuxCNC from using that as a means of connecting to any boards or motion controllers.

Since LinuxCNC can use Mesa cards, for example, I would think that WiFi might be included as a means of connecting those cards by default. There must be a way to prevent the LinuxCNC process from including WiFi among the possible means of connection and thereby avoid any jitter while still having WiFi available to other non-real time processes like web browsers and email.

I sure wish there was a GUI that would display all connections and processes for that matter, and allow enable/disable for choosing whether each of them should be real-time or not. It sure seems like the Unix gurus the world around despise GUI dependent dumb-dumbs like me!

In my experience, its very unusual for hardware on Linux Mint to not be Plug and Play. Many drivers use proprietary code that the manufacturers will not release to the LInux developers. There is an option when installing Linux (pretty sure Mint asks for it) to install 3rd party extensions. This provides support for these 3rd party drivers.

And yes, Linux sorts out the routing between a motion card and a wifi connection if you set the network connections up correctly. Latency can be affected if you use onboard wifi controllers on many of the USFF PC's so you need to use a USB dongle on these.

But unless you type lsusb at the command line you are all flying in the dark!

rodw, do you mean lsusb?

pmconsulting wrote: rodw, do you mean lsusb?

Yes, sorry my typo

machinedude wrote: i did come across some info on USB WiFi and Linux and this one does seem to work with Linux but i would need to install the driver first..

I suggest getting one of the many WiFi dongles sold for the Raspberry Pi, as those typically work with the drivers already included in Debian.

I'm trying to follow this install and everything works as described when installing the kernel, but when I try:

"Restart, hold down shift and ctrl to show grub2 menu, choose the above kernel"

I do not get to the grub2 menu and after some time I get the following error:

Could not update ICEauthority file /home/jj/ICEauthority

Is there another way to get to the grub2 menu now?