Advanced Search

Not exactly sure what this is all about, but
1. RPI is not a good choice anymore, there were several hardware versions of RPI5 with many issues
2. There is a ready made image for RPI5 that works out of the box
3. SPI does/did not work at all on RPI5, but Scot has done some work on it so by now it probably works
4. To expensive for what it is
and personally (after buying 3 of RPI3)
5. having a very small SBC controlling a big machine is ...
6. to damn weak for comfortable use
7. to much hoops to jump just to get things working, so utmost respect for whoever made the images
8. for the same price a good used PC or laptop can be bought, and everything works.
-
As for making user experience better, utmost respect, see with ScotA if he needs help with SPI

Thank you cornholio.

I'm looking to cut wood for building boats.

If I run into issues doing the above well, I earned a living doing Unix driver and kernel work a while ago; I would like to contribute now if I could. I have experience with a number of device driver debugging and kernel development techniques.

Let me get some hardware and software in. Again, if there is a certain feature that doesn't work that should work, let me know.

Thanks,
Tom Alborough

You coming at this arse about. Which makes me wonder if this is for academic purposes, a potential commercial endeavor or a tech blog.
First one decides on the type of cnc machine they want to build, then they choose the controller to suit.
The simplest entry point for one who has no plan for their actual "cnc machine" would be.

A Lenovo M73e tower, preferably with an i5, the appropriate MB to Parallel Port cable ( there's some trickery with the cable that enables the PP hardware) and a generic Parallel Port breakout board. I've recommended this combination as I know it works, I have tested it with a lathe for basic functionality. I actually found this machine on the side of road with a celeron processor, which I swapped out for an i5 (3470 I think) and an SSD from the "useful box".

What people want is something that will run their hardware (their cnc machine be it a plasma cutter, lathe, mill router, laser tube profiler, PnP machine, cnc soldering machine) at a price point they can afford. As you can guess this is quite an expansive list.

Hello cornholio,

I get your point.

I would like to buy (some kind of a) Raspberry Pi 5 and the electrical hardware needed to make a CNC machine. The reason I'm writing to you is to ask you this: What should I buy? I'm not looking for a configuration that works. I'm interested in a configuration that people want to work. What hardware do the readers want to load software on and run without any hitches?

Thanks,
Tom Alborough

If you want true "as easy as an installing an app on your cell phone" buy a commercial cnc machine from one of the Big Boys.

This is all I have left to say on the matter.

Hello cornholio,

Thank you for your reply!

I see your point about "AI".

In your reply you separated the "CNC" part of the task (feed speed, etc.) from the "system" part of the task (boards, drivers, etc.). I agree with your split and then assert the "system" part of the solution should "just work".

LinuxCNC on Pi 5 should work as easily as say Google Maps on Android, with no system experience required to install and use the application.

Do you see folks in this thread who believe a better experience is possible? Who exactly would champion a better experience for Pi 5 and LinuxCNC? I believe many of the people who answer the system questions posed in this thread would also be contributors to an effort to revise the code. I have seen similar efforts succeed.

Let me know!

Thanks,
Tom Alborough

Economically the RPi5 or RPi4 is not a great choice when compared to an ex corporate PC. The only advantage is a very small foot print and the ability to use a SPI interface board.
 

Hello cornholio,

Thank you for your response!

Have you read the entire thread ? I have browsed the beginning and the end of the thread. I noticed the need for both new and experienced users to ask for and get high-level support from this thread. My observation is that over time, it would be good for the need for high-level support to go down rather than stay the same or go up.

I have seen situations like this and I have seen a group of people improve the situation. I would be happy to talk more about it.


Have you downloaded and written the LinuxCNC image to an SD card ? I have done the exact same thing with a variety of mass storage devices and operating system images.


What hardware are you wanting to use ? I haven't gotten to with that yet. My observation is that (ChatGPT) is warning people away because the Pi 5 / LinuxCNC combination has issues.


What is your end goal ? I would like to buy (a Pi 5) and some popular controller and stepper motor hardware and load LinuxCNC with as much as much of a chance of success as loading and running an application on my cell phone.

(-- Out for the evening...)

Thanks,
Tom Alborough

Have you read the entire thread ?
Have you downloaded and written the Linuxcnc image to an SD card ?

What hardware are you wanting to use ?

What is your end goal ?

Hello,

I have run into a need for LinuxCNC. I'm wondering if some kernel / device driver work is needed for supporting LinuxCNC on Pi 5. I would look for a user to be able to download, install and use the software without high-level technical support.

Please let me know your thoughts.

Thanks,
Tom Alborough
----
Some of my related work:

"Thomas Alborough Unix" - (Use citations that contain "Unix" and "Alborough")
"Thomas Alborough Guide to Writing a Unix Device Driver" - (Search for "Alborough")
LinkedIn... Search for "Thomas Alborough"

This is the download link

drive.google.com/file/d/1pmV587gXFEvznQB...00x/view?usp=sharing

Something has changed on linuxcnc between then and now, but not much.
In particular, the function for using GPIOs which was previously hal_pi_gpio and is now hal_gpio
linuxcnc.org/docs/devel/html/drivers/hal_gpio.html
forum.linuxcnc.org/24-hal-components/504...-with-raspberry-pi-4

The image of RaspiOS with Linuxcnc is available in this link

forum.linuxcnc.org/9-installing-linuxcnc...pi-5?start=40#303752

Let me know if you need further guidance

Use the one Rod linked to on his google drive as it handles screen resolutions much much better.

With Linuxcnc is somethings works generally users stick with it. There is still many machines running earlier versions of Linuxcnc on Ubuntu 10 series.

Think of a machine running Linuxcnc the same as an ECU on a pre 2000's car or bike, if it works don't mess with it..........unless you're racing

You can connect TTL level encoders directly to 7C81 I/O pins
_but_ I would at the minimum add say 220 Ohm resistors in series
with each signal to protect the inputs from negative input spikes.
(encoder signals tend to pick up motor drive noise so are fairly hard
on unprotected inputs)

I'll answer with experience of using Aliexpress Omron type encoders www.aliexpress.com/w/wholesale-omron-rotary-encoder.html , which are about less than a tenth of the price of the ones you mentioned, it's nice if you mention parts you can provide a link, saves time trying to search and ensures the correct component is being discussed.

With an optocoupler you will need to ensure the optocoupler is fast enough and the encoder can drive the optocoupler's led hard enough.

If the encoder is true TTL output or open collector output it should be fine.

Personally I've just used simple buffers, 74hc540/541, as I have a couple of tubes of them.

Another option would be to use the differential output of the encoder and connect that to a differential line receiver, such as www.futurlec.com/Linear/26LS32pr.shtml.

The schematics for the 7c81 are available, forum.linuxcnc.org/media/kunena/attachments/481/7c81sch.zip , one of the sheets shows the input circuitry.

No doubt Pete from Mesa will chime in.

Hello

I have a question about connecting the encoders in the set:

RPI4 + 7C81 + Mach5 3-axis board.

Since the 7c81 documentation says about a 5V tolerance (inputs), can I connect the encoders directly to the 7c81, or is it better to protect them with an optocoupler?

Will the encoders:
ROD426
ROD420
be suitable?

Thanks in regards, 
Michal