Raspberry Pi 4

Tried lots of options to get rpi4 working -Good news and bad news. It ran once from desktop icon created by pnconf but not again.
Followed above suggestions to create a static IP - followed a couple of tutorials (both similar in that they used dhcpcd). That didn't fix the problem if I did things correctly.....
After a couple days of trial and error frustration I created a new image on an SD card. Before running pnconf I disabled wifi (didn't do that originally) and set ipv4 to 192.168.0.1/16. In first try that failed was set with /24. Disabled ipv6. Then ran pnconf using settings I know work on my system.
And voila everything worked.
But after shutting down and powering up - back to same error as before. Nothing seemed changed in the IP setup. Double checked address of mesa7i76e in the hal and ini. All looked the same but no go.
Will try another round of same tomorrow but sure would like some insight into what is wrong and or fragile in the process.
Thanks,
Dennis

Getting this working on my RPI 4 required just adding the bottom 3 lines in the etc/network/interfaces file:

# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto eth0
iface eth0 inet static
address 10.10.10.100

This is following the suggestions in the hm2_eth manual.

thankyou ..... Iwill try tomorrow (side note - on a third image burn test it would run once and then quit from a reboot as opposed to second round that quit after power down/up. I don't fully understand the iface eth0 inet static above but I will look it up - sounds like as you first suggested I have changing ip address issues.

Below is latency-histogram from my RPi4. I think its usable, but I've seen better posted here.

I did this while running running remote desktop over the on board WiFi. Probably not the best thing. When I actually start using LinuxCNC I will have a dedicated display and keyboard.

I'm using the on board LAN to connect to the 7i92. I've heard that the onboard WiFi can increase latency. I still want internet connectivity.

So, the question is, what's the recommendation for a USB LAN dongle? Traffic on this LAN connection should be light, and if necessary, unused while LinuxCNC is active.

Hello
I write the image for the RPI4 from the LinuxCNC Homepage to the card.
When I Start the rpi I get this error: => see picture
Then it automatically restart an start normal
What is the problem ?

it means that your CPU doesn't support hardware virtualization

help.ubuntu.com/community/KVM/Installation

Not a LCNC problem. Ask the Rpi4 Linux devs.
github.com/raspberrypi/linux/issues/2299

Do they use different CPU for the rpi4 ?
Or does all user with an rpi4 have this problem (with this Image from the LCNC HP) ?

I think you just need to disable KVM (or use a kernel that has it disabled)
The warning is harmless

I just built an RPi4 image using John Thornton's guide. Works well as expected ... 50uS max latency w 4glxgears after 16hrs. But the recipe gets you 2.8.1, a little confusing but easy to adapt. Should/Can we substiture 2.9 in "git checkout 2.8" ?

Also the gpio driver from MX_Master has the reset function, allowinfg doubleStep for the OrangePi that he targeted. Can this code be adapted for RPi ?

I have not read all 47 pages of postings but wanted to jump in here. I have a modified version of PICnc-V2 running on the Pi4. I think it can get the rates you are looking for. In my testing I see the linuxcnc 2.9.0 is generating motion commands at startup. Very small but the machine is in estop. If you run the stock gcode and stop the machine with the power or estop switch the system continues to generate motion at what ever velocity it was at when you stopped. Very dangerous. Thankfully the only thing I have connected is test equipment.