RPI4 Raspbian 64 bit & LinuxCNC

is there a more current 64bit image than the link above or is this the go-to?

Thank so much

You can find the latest versions of RaspBianOS 32 and 64 bit with the patch for PREEMP-RT or low-latency at this link

github.com/kdoren/linux/wiki.

The installation and building methods are also reported

Following what is reported in this link

github.com/kdoren/linux/wiki

I prepared an image of RaspiOS64 based on realtime Kernel 5.10.74-rt54 with version 2.8.2 of LinuxCNC.

The image can be downloaded from this link

linuxcnc-2.8.2-pi4-arm64.zip

LinuxCNC 64-bit deb packages (compiled for 64 bit OS) are also available:

for version 2.8.2

Linuxcnc_2.8.2_arm64deb.zip

and 2.9.0~pre0

Linuxcnc_2.9.0~pre0_arm64deb.zip

Is RTAI kernel still not possible on RPI

There is no current port of RTAI to any ARM CPU. It would take lots of work to do so and not sure if it would provide a much lower latency than preemp_rt or Xenomai.

We ran Xenomai on some Allwinner ARM processors about 7 years ago. Latency was around 40,000nS.

Allwinner and Rockchip both make ARM SOC's with integrated microcontrollers. It has already been proven to work on the Allwinners to offload the real time tasks to the integrated micros. forum.linuxcnc.org/18-computer/39037-lin...-orange-pi-allwincnc

This is similar to using the PRU's in the Beagle Bone Black ARM SOC.

Please compile 2.9 with this hal_pi_gpio

Replied by tjtr33 on topic Raspberry Pi 4
I have posted the src file for a new hal_pi_gpio that has
inputs, inverted input
outputs, inverted outptus reset outputs ( allowing double step for rpi opi bpi )

this forum is hard to follow so i have not ( this morning ) found where i posted it .
so, here it is again
the 'easy' way to build it
is to do it in a RIP
cd
cd yourRIPdir
. scripts/rip-environment
( yes thats DOT SPACE before the 's' )

find your old hal_pi_gpio.c file
remove it from 'that place'
store it away for safety
then put my new hal_pi_gpio.c file in 'that place'
then 'touch' it to isure it's 'new' and will be compiled
touch hal_pi_gpio.c
go back down to the src dir
sudo make modules

its only a few seconds to finsih

now use it
in a hal file
loadrt hal_pi_gpio pi_pins=\
{3,>,0,Y}{5,>,1,N){11,<.+,x}

that makes pin 3 an ouput with initial value 0 and is resetable
and make pin 5 and output with initial value 1 and not resetable.
and makes pin 11 and input with and additional inverted pin ( th x is just a place holder for nice columns of print )

read the code to see more
some of the pin 'features' are enabled with these {...} sets
so the feature still needs to be turned on
like
loadrt hal_pi_gpio pi_pins={40,>,1,Y}
will creare a resettable pin
BUT you need to say
setp hal_pi_gpip.pin-40-out-reset 1
to turn on the feature

hth
tomp



forum.linuxcnc.org/18-computer/36879-ras...-pi-4-mmap?start=480

I have compiled 2.9 with doble step hal.pi.gpio.c.
Mine version have weared DRO and have some errors popped up frequently.
Elovalvo you are genius in doing so.
Please compile 2.9 version with that.

virencq wrote:

I have compiled 2.9 with doble step hal.pi.gpio.c.
Mine version have weared DRO and have some errors popped up frequently.
Elovalvo you are genius in doing so.
Please compile 2.9 version with that.

Good News.
I recompiled version 2.9.0pre of Linuxcnc for ARM64 and the .deb files are available here
LinucCNC 2.9.0pre .deb files

It is necessary to copy to the '/usr/lib/linuxcnc/modules' folder the hal_pi_gpio files (old and new) that are attached to this post
forum.linuxcnc.org/9-installing-linuxcnc...-bit-linuxcnc#230690

where the methods of use are explained and also a test of operation by halrun of two servos.

the libks for download those files not work.

COFHAL wrote:

the libks for download those files not work.

Are you sure? I tried and they work