Cubieboard 2

Hello fellows,

I'm starting my work with the linuxCNC on a college work and I have install a lcnc on a Raspberry, so than the possibility of use this version on a cubieboard seems to be interesting, but I need the expirience to solve that problem

I have built in a image from debian Wheezy how is the most closer of the RPi, but I have problems to run the program, I follow that steps, www.raspberrypi.org/phpBB3/viewtopic.php?p=399603#p399603 and everything so far was working till the point how I chose the sim axis configuration and the software break's and close, someone is working with that board too?

thanks

Hi

I follow that steps, www.raspberrypi.org/phpBB3/viewtopic.php?p=399603#p399603

Does this mean you have done a latency test from /usr/lib/xenomai/testsuite/latency and it works OK?

everything so far was working till the point how I chose the sim axis configuration and the software break's and close,

You will need to post the precise errors that you get and we may be able to tell you if the problem is in linuxcnc or if it is your system.

regards

Hello ArcEye, sorry by my late,

I was testing a few theorys regarding that's errors, the problem was solved I managed to put to work, but cost to me one entire day and a several cups of coffee, but I think that solution could help everybody what will work with that platform.

It was, simply the python libraries, i thought that's the problem was on the kernel, because the cubieboard doesn't boot like the raspberry with a partition mounted on /boot , he has a u-boot and the allwinner's developers have not distributed that codes yet for rebuild-it. The steps on the link work very well, if someone will try, my suggestion is to follow that instructions and install the python-tk libraries.

fortunately the problem was not in the kernel, I was managed to perform a latency-test on a cubieboard2 without any problem, I'll post a picture of that running, I still making the HAL patch's to run the step/dir commands over GPIO, so, soon I will publish my results.
I will like to have some sujestions, some material i could use as base for my research.

and sorry by my english, I'm from Brazil and here is too difficult to find someone who is trying that kind of thing, and thanks to the effort of each one of you I now am able to test all that things.

Thanks for the help boss

Glad you sorted it, yes there are a lot of python libraries required these days and because they are referenced from run time scripts, the missing dependencies often don't show up until you try to run something.

That is some serious max jitter you have there (5.2M)

Will be interested to see how it runs

regards

I'm guessing the huge latencies are because thats a stock kernel, not a RT kernel

CaptHindsight and Memleak on IRC managed to get either
Xenomai or Preemt_RT running on the Cubie2 with ~ 80 usec latency IICRC

I think so, I still new on that linuxCNC business,

there is any documentation about the work of those guys? It will very helpful.

I dont know, I got the impression this is for something commercial so not immediately published, you can always ask the principals on IRC

Heres the IRC log

psha.org.ru/irc/%23emc-devel/2014-01-27.html

(search for cubieboard)

Hello

The problem is exact on the kernel, I test it over this last days and when I run the latency-test on the RPi I get 97,231ns of maxJitter on the Base Thread and 82,954 on the servo,
Indeed don't look's like very good but the idea is tu use a external stepgen or possibly a external 10+10V reference for each axis, I'm looking to the project of Kinsa using a PiC32, but as I don't have the gratest notion of the HAL files or the PIC maybe other ARM platform will be use

I finaly found a RT for cubieboard 2, I'll try in the next few days to see how good it works, I stell have de idea to use it even for a 3D printer, how don't have a good requirements, but in my project I want to use it to controll a lathe.

You guys he much more knowledge than me, any suggestions?

We are working on the A20 now. The ~80uS max jitter was with a preemept_rt kernel.

A port of RTAI to the A20 is just starting.

The A10 has coreboot support and we'll probably have it for the A20 and cubieboard2 soon.

We started working with the current distros for the cubie but the ISO's were so full of broken packages and tool chains that we just decided to start from scratch and do it right.

Stay tuned for updates.

Any updates? I find these low cost boards to be fascinating as we are very near being angle to reliably implement a CNC controller for less than $100 on new hardware.