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This image can be downloaded from here
drive.google.com/file/d/16kKamxMKPdYAeJp...KLf/view?usp=sharing
At first glance everything seems to work regularly and the lowest value that did not show the "Unexpected realtime delay" message was
latency-test 12000

Trying your image now. ... what username and pw does it take?

rodw post=287637 userid=20660I did a bit of reading. can you guys try adding this at the beginning of cmdline.txt?

video=HDMI-A-1:1920x1080M@60D 

I also noticed that the RT patch 6.1,66 has been released and the 6.1.66 kernel was merged into the 6.1.y branch yesterday so it would be a good time to build another image.
 

There was no cmdline.txt. Creating one with this line didn't change anything.

I think that the images built with the rpi-img-build are missing some grahpics libs that are included with the Raspberry Pi OS. When the RPi5 is booted with your image and you go to change the resolution there is no monitor info there. There could be a problem with the EDID being read, so it doesn't know what monitor\display it is working with.

Just remember rod that the RPi5 is a different beast compared to the RPi4.

chuckp47 wrote:

Hello. I'm new to the forum. During the day I'm an embedded firmware guy. I've built products using the RPi4 (CM4) and an Olimex Lime board. I want to use LinuxCNC to control an ornamental lathe. I've got an RPi5 here now, as well as a Mesa 7c81 with an RPi4 on its back. I know I have more questions than I can post right now, but I look forward to learning more here. I'm particularly interested in how the RPi5 port is coming.

Here's the result of the latency plot on the 4G RPi4b running the LinuxCNC 2.9.1 Debian 12 Bookworm PREEMPT-RT ISO.  Doesn't look too good,  Is this normal?  We're planning to use DM542 style drivers, so maybe it doesn't have to be perfect, but...  I guess I should try the RTAI based one.  Or maybe I should just jump into the RPi5 project?

 

Just run the latency test without the base thread. There's no need for a base thread when using a Mesa card.
Be warned the hm2_rpspi driver does not work with the RPi5, it requires a rewrite to suit the RPi5 hardware, IO has been moved to the RP1 chip rather than being on the processor itself, I spent a while with this, hence the reason the RPi5 is in a drawer ATM. If you want to reduce the latency disable sound, wfi & bluetooth.

I did a bit of reading. can you guys try adding this at the beginning of cmdline.txt?

video=HDMI-A-1:1920x1080M@60D 

I also noticed that the RT patch 6.1,66 has been released and the 6.1.66 kernel was merged into the 6.1.y branch yesterday so it would be a good time to build another image.

chuckp47 wrote:

Hello. I'm new to the forum. During the day I'm an embedded firmware guy. I've built products using the RPi4 (CM4) and an Olimex Lime board. I want to use LinuxCNC to control an ornamental lathe. I've got an RPi5 here now, as well as a Mesa 7c81 with an RPi4 on its back. I know I have more questions than I can post right now, but I look forward to learning more here. I'm particularly interested in how the RPi5 port is coming.

Here's the result of the latency plot on the 4G RPi4b running the LinuxCNC 2.9.1 Debian 12 Bookworm PREEMPT-RT ISO.  Doesn't look too good,  Is this normal?  We're planning to use DM542 style drivers, so maybe it doesn't have to be perfect, but...  I guess I should try the RTAI based one.  Or maybe I should just jump into the RPi5 project?

If you are interested with a Pi 5 and the image you find here
forum.linuxcnc.org/9-installing-linuxcnc...pi-5?start=60#287616
the graph of latency-hystogram is this
 

thadwald wrote:

Well ...
I added the network-manager-gnome package in order to get the GUI nm-applet.

I also added the raspberry pi repository 
deb archive.raspberrypi.org/debian/ bookworm main
so I could get raspi-config

isolcpus 2.3
Max latency during a short test was about 15us
I hooked it up to a MESA 7i76s and just worked. So no network latency issues (yet).
I'll let it run for a while.

The 640x480 display limit is a bugger. Any idea how to fix that?

It does run pretty warm. 
Processor utilization running gcode in Axis is around 15% for cores 1 and 2


 

No solutions as of yet, I think its related to not being able to read EDID of the display. Raspberry Pi OS is fine. Which, IMHO, does feel a little snappier, but that's just a "seat of the pants" feeling.

Why are you running such a low servo thread ?

If you are running Wayland just be wary that any apps that make calls to X lib functions will be a little, ahem, slow.

There is an option in raspi-config to change from Wayland to X.

Taking into account that a new version of RaspiOS has been released
(www.raspberrypi.com/software/operating-s...spberry-pi-os-64-bit)
Release date: December 5th 2023
System: 64-bit
Kernel version: 6.1
Debian version: 12 (bookworm)

and the new Preempt_RT patch
mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/6.1/

I prepared a new image for the Raspberry Pi5

Linux raspberrypi5 6.1.65-rt16-v8-16k-elv_rt+ #1 SMP PREEMPT_RT Thu Dec 7 13:43:31 CET 2023 aarch64

in which I installed a version of linuxcnc_2.10.0~pre0_arm64
forum.linuxcnc.org/9-installing-linuxcnc...xcnc?start=20#287208

This image can be downloaded from here
drive.google.com/file/d/16kKamxMKPdYAeJp...KLf/view?usp=sharing
At first glance everything seems to work regularly and the lowest value that did not show the "Unexpected realtime delay" message was
latency-test 12000

The values ​​are much better than the version here:
forum.linuxcnc.org/9-installing-linuxcnc...-pi-5?start=0#285243
 

Well ...
I added the network-manager-gnome package in order to get the GUI nm-applet.

I also added the raspberry pi repository 
deb archive.raspberrypi.org/debian/ bookworm main
so I could get raspi-config

isolcpus 2.3
Max latency during a short test was about 15us
I hooked it up to a MESA 7i76s and just worked. So no network latency issues (yet).
I'll let it run for a while.

The 640x480 display limit is a bugger. Any idea how to fix that?

It does run pretty warm. 
Processor utilization running gcode in Axis is around 15% for cores 1 and 2
 

thadwald wrote:

By the way, DigiKey has over 2500 pi5 4GB in stock. $60 plus shipping.

 

Unless you are going to use Ethernet or prepared to wait for the hm2_rspi driver to get rewritten I wouldn't grab one right away. And due to the need to really run a cooler, fitting to the 7c81 is going to need a bit of ingenuity.

Yep the display is an issue.
I started with downloads.raspberrypi.com/raspios_arm64/...ookworm-arm64.img.xz

Installed XFCE desktop, used the config to use X instead of wayland then built a RT kernel to suit.

By the way, DigiKey has over 2500 pi5 4GB in stock. $60 plus shipping.

Thanks.
First thing I notice is display is limited to 640 x 480 and I cannot change it via the Display GUI.

usr cnc
pw  cnc