Advanced Search

I’m using a raspberry pi 5 8gb with the latest 2.93 image that’s linked on the first page of this thread. I’ve attached a screen shot of what I’m getting when run the commands. 

Wow, thank you @cornholio! That will make it much easier for us
@PCW thank you as well for the info.

Did you run the commands I suggested and post the output ?

What RPi are you using ?
What Linuxcnc img are you using ?

It’s only showing 11 & 12, I can’t get 1 to show.

I’m pretty sure I’m using the latest kernel though.
6.6.44-rt39

Too hard to edit

[ls -la /dev/i2c*[/code]

Would be good to see permissions, not that should affect sudo.

I'm working on a Rpi5 with an image I built myself from rodw's image builder

This is my kernel.
Linux raspberrypi 6.1.69-rt21 #1 SMP PREEMPT_RT Fri Jan 17 10:39:48 AEDT 2025 aarch64 GNU/Linux

Before I finalised my post I checked running by running
As I have nothing connected I got this:
sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --


What doesshow ?

/dev/i2c-1 /dev/i2c-11 /dev/i2c-12

I was able to enable i2c, but the instructions say use “sudo i2cdetect -y 1”, 1 doesn’t seem to exist for me, I can only detect 11 and 12 and neither show the 0x36 address.
I have confirmed that the pins are making good contact, so bad connection is ruled out.
Could it be the kernel configuration?

To turn on i2c

edit as superuser /boot/broadcom/config.txt and uncomment the lines relate to i2c.

then edit as superuser /etc/modules and either add i2c-dev or uncomment if it is commented out

reboot

That will get i2c up and enabled

Hey guys, I’ve add a Geekworm x1201 UPS to my Pi5 as I often get power outages at my place and wanted a bit of extra security.
I was able to access and change the EEPROM to get it to charge and power the pi5 from the batteries. But to change anymore detailed settings, like battery monitoring, It’s telling me I need to open Raspi-config. Which I obviously can’t using the Linuxcnc image. 

Here a link to the detailed instructions, suptronics.com/Raspberrypi/Power_mgmt/x120x-v1.0_software.html
unfortunately it’s all for the Raspberry Pi OS. 

Is there anyway I can make this work or am I wasting my time? 

 

The biggest issue is that Linuxcnc will require building from source as the RPi5 images don’t have Linuxcnc packages built from the most recent code base. Editing config.txt to turn on spi is a trivial matter.

Give me a day or 2 and I’ll generate an image with the most recent Linuxcnc & Mesaflash.

The 7C80 will work with the RPI5 using the hm2_spix driver.

Note that some 7C80s were shipped with firmware that does
not work with the RPI5. These cards can be re-programmed
on a RPI4 if that's convenient. All the distributed bitfiles are OK.
 

Hi all, 
after swapping our Raspberry Pi4 with a 5 things didn't work anymore as they did before, and thanks to this forum, as far as I understood there is no SPI support yet, right? 
I have also read that "rodw" you have created an image builder, and "Cornholio" you managed to patch it so it works right?
As we are trying to run the mesa 7c80 with a Raspberry Pi5, is there an image available currently that supports this combination? If not what would be the steps to "patch" it together? 

Thanks a lot in advance 

With the 5A-75B and 5A-75E we have a low cost way of creating a driver board for Linux-CNC. Based on the work of Romanetz, the project  LiteX-CNC  was started, providing a easy customizable firmware and driver to use these boards. The down-side however is that these boards require some soldering work to be done to accept inputs; I've messed up some boards in the process....

Therefore, Litex-CNC is going to be expanded to accept more FPGA's, starting with the Sipeed Tang Nano 20k. Compared with the 5A-75B it has less outputs (28 compared to 48 for the 5A-75B), but this is still enough for a simple 3 axis machine. The big advantage is that no SMT soldering skills are required to get this board up and running.

For the Raspberry-Pi I've designed a HAT, which provides:

• 7 extended PMOD-connectors. Each connector has 4 GPIO, power rails (+5V, max 200 mA) and a buffered enable signal;
• RS489 connector for communicating with for example a VFD;
• communication between Raspberry PI and FPGA using SPI in bidirectional mode (3-wire) to save on pins;
• conforms to the HAT+ specification , including a EEPROM with settings.

With the PMOD-connectors one can easily connect to break-out boards providing stepgen, GPIO (12V/24V inputs and outputs), differential encoders, etc. I'm also working to provide support for shifting data out (74HC595) and in (74HC165).

An estimation of the HAT will be around 7 Euro's, excluding the Tang Nano 20k. Inlcuding the FPGA, the price would be around the 40 Euro price point.

I am new to LinuxCNC, so please forgive me if this has already been answered.  I searched and could not find it anywhere so am asking here.  (I always hate on other forums when people just jump in with questions before searching.)

I have a 7i92TH connected to a Raspberry Pi 5.  The use case for it is for rose engine lathes, and we need to drive a spindle + 7 axes.

The break-out board we are using for both 26-pin outputs from the 7i92TH was developed using the input from Peter.  Fundamentally, we will have

• 8 outputs to drivers, all with Step, Direction, & Enable
• 7+ inputs for limit switches

Peter W. got us setup with the files needed to program the 7i92TH, and that seems to be working as expected.  When I run

         mesaflash --device 7i92t --addr 192.168.1.121 --readhmid

the output matches the .pin file supplied by Peter, telling me that the mesaflash --write command worked to load the .bin file supplied by Peter.

When running pncconf:

• I've tried with copying the contents of the .pin file into the Input tab on the Help screen, and not doing this.
• I was able to successfully discover the 7i92TH board, and it populated the Output tab on the Help screen (I didn't check word-for-word, but it seems to be duplicate of the output from mesaflash --readhmid).

When I want to proceed forward, assigning the pins to axes, I encounter the screens I've attached.

ISSUE for which I'm seeking help:  I can't figure out how the Num items (pin numbers?) match up to the .pin file.  What am I missing?

Rather than starting a new thread about jitter mitigation, I'm just going to add it here.

First, I'm keeping in mind that Peter Wallace said " The jitter is basically unimportant with a 7C81 unless its so bad you
get real time errors at the normal servo thread rate ."

I'm also treating the Raspberry Pi + 7C81 as a dedicated controller, not a PC. By that I mean I'm not going to be doing anything on the Pi except LinuxCNC. I may turn on WIFI to update packages, or use email to transfer a file. But I plan to even turn off WIFI before I launch LinuxCNC.


I ran several tests to see which combination of settings offered the most optimized jitter. I ran two Glxgears for all tests as I though that was reasonable, and ran the tests for long periods of time unless they looked bad early on.

I thought that turning off all unused services would decrease Jitter. So I turned off 9 of the 23 services, such as CUPS, Bluetooth, etc. To my surprise this did not decrease jitter.

Screen blank increased jitter a bit, so I turned that off. It doesn't make much sense anyway on a CNC controller.


These are the settings I added to the line already in /boot/firmware/cmdline.txt:
I tried a few others that some people recommended on various blogs. Nothing else I tried had any noticeable positive impact on jitter, and some noticeably slowed down the responsiveness of the Pi.


Turning off timer_migration did reduce jitter. What I read said that you could make this setting permanent by adding it to the boot command line, or setting it in either of two different system files. Oddly none of that worked. So I setup a cron job to disable it at boot, and that works.Add the following line:

The other thing that helped reduce jitter was changing the scheduling policy to real-time and increasing the priority. I decided to create a shell script to launch latency-histogram, and eventually linuxcnc, which changes these things on the process.
I named it rrt (run real-time). So to launch latency-histogram it's simply:
All spawned sub-processes inherit the policy and priority. So if linuxcnc is launched with rrt:all of the processes that are part of LinuxCNC have the policy of SCHED_RR and priority of 99. I used Round Robin scheduling to make sure no LinuxCNC process "starves" another.

I don't know if this will work in the end, but I'm going to give it a try. Nothing ventured, nothing gained.

Implementing all of these, here is the jitter histogram. Good enough.