Installing LinuxCNC 2.9 on Raspberry Pi 4B with Preempt-RT kernel

Dear All,

With ongoing extensive testing, of this kernel
Linux linuxcnc29 5.15.84-rt54-v8+ #1 SMP PREEMPT_RT Fri Dec 23 20:39:48 CET 2022 aarch64 GNU/Linux

Unfortunately, I have found few problems.
1. the virtual keyboard was not found by gmoccapy.

The solution was the installation of onboard and pygst
$sudo apt-get install onboard
$pip install pygst

Note:
The matchbox-keyboard in this kernel is defective

2. In gmoccapy when loading png the error box pops up:

Found an error!
The following information may be usefull in troubleshooting
File "/usr/lib/python3/dist-packages/gladevcp/hal_filechooser.py", line 56, in update
m=progress_re.match(stderr_line)
TypeError: cannot use a string pattern on bytes-like object

Solution:
TBD , we need to ask developer of gmoccapy.
However, the “axis” imports and processes the png’s and py’s OK

Thanks,
RMS

Thanks for the report

1. I'll add that to the instructions

2. There may be a quick fix for that. Try this:

- Open file /usr/lib/python3/dist-packages/gladevcp/hal_filechooser.py
- Change this line
    stderr=subprocess.PIPE,
to
    stderr=subprocess.PIPE, text=True,

Alan
it works thanks
RMS

P.S.1.      With the overclocking I suggest being cautious.  I was experiencing stability problem on CM4 and had to revert and clean cmdline.txt and config.txt from overclocking entries.
2.      While loading button macros with custom ‘png” graphics i am getting error. File “/usr/bin/gmoccapy”, line 5728, in <module>  app = gmoccapy(sys.arg)
...
File “/usr/bin/gmocappy”, line 1397, in_check_macro_for_image Image=line.split(“.”)[1] IndexError: list index out of range

Any clues? 

Good to hear.

1. I've added a note about needing an very large heat sink. I've been thrashing my RPi for a week straight now without problems.

2. I'll take a look and get back to you

Alan,
Thanks.
The instability I was experiencing was particularly related to network connection.
The CM4 has heatsink with a fan attached, so there must be some other type of issue.
BR,
RMS

alangibson wrote:

1. I've added a note about needing an very large heat sink.

I have had decent results with the passive heatsink cases:
www.amazon.co.uk/dp/B082Y2RGMP
I haven't tried this style, but it looks like it might be at least as good, and it's more of a case.
www.amazon.co.uk/dp/B08L8M6GJ7

(Not promoting any particular supplier, just indicative of the style of case I am talking about)