Reply with QuoteThat's awesome. Unfortunately, I apparently won't have mine until september according to my supplier's expected ship date. I have been looking into the RTAI and EMC stuff in the interim. Both look to be do-able.
Well, here I am, talking to the forum using a Raspberry Pi! It's running a Debian Squeeze image from a 2GB sdcard, LXDE GUI, Iceweasel (a.k.a Debian port of Firefox). FullHD HDMI display, wireless USB keyboard and mouse, cabled ethernet (for now - nano wireless dongle on order).
It's so incongruous - huge LCD TV, keyboard and mouse, but look to my right and teeny credit card sized computer.
To be honest performance with all this stuff is very laggy. Partly it's because the display drivers are software only (this Debian port doesn't support the GPU yet), and fullhd in software is a bit of a trick. SDcards are slow too, so that's bound to have an effect. Plus it's only a single core, and we PC users have got used to multi core CPUs where you never notice that its busy. Still, if this can run a modern desktop OS entirely in software at an almost acceptable speed, it'll have no problem at all doing CNC!
Last edited by mpack; 05-08-2012 at 11:05 AM. Reason: fix typos.
That's awesome. Unfortunately, I apparently won't have mine until september according to my supplier's expected ship date. I have been looking into the RTAI and EMC stuff in the interim. Both look to be do-able.
I'd hold my enthusiasm until you actually get RTAI and LinuxCNC installed, and actually run a latency check.
Mark
I don't think I will hold my enthusiasm. Without enthusiasm for such things we would not even have hobby CNC at all, and would still be cranking handles by hand. Or, at a minimum, we would still be running very basic CNC controllers on x86 based processors and just say that that is good enough. Enthusiasm has bred the types of controllers we have now with graphical representations of toolpath, with functionality that rivals even production based CNC controls.Originally Posted by wendtmk
I'd hold my enthusiasm until you actually get RTAI and LinuxCNC installed, and actually run a latency check.
Mark
If the miniemc2 project is any indication, it has already shown that it can be done on an ARM9 board. Although that project is still in development, all of the source is available and it is working using the GPIO of that board.
Obviously there is much work that needs to be done to make it happen on a RPi, but without enthusiasm it will never get there. I'll keep my enthusiasm high.
Notice I said "my" enthusiasm. Go for it. I'm anxious to see the results.
Mark
Unfortunately Linux kernel development is just one of the many subjects of which I find myself on the wrong end of the learning curve! Reading about it now.
I'll check out the miniemc2 project for pointers.
Running LinuxCNC on the raspi sounds extremely exciting! I have always thought using a "real" PC and the parallel port as a CNC controller a total kludge (don't get me wrong, it seems to work great but from an engineering point of view). It's cheap, has a small footprint etc. I hope LinuxCNC gets ported fast!
raspberry pi emc simulator is working I think???
I have been searching for more info about getting the real time kernel running on raspberry pi and found the thread here on cnczone, unfortunatly I have not found anything in terms of an easy compile for RTAI on ARM.
But I thought I should post a cross link to emc2 on raspberry pi as far as I have got. The real time kernel could be very hard, I don't have enough expertise to know yet, but I managed to compile emc2 in simulator mode without RTAI last weekend.
Raspberry Pi • View topic - Real-time linux kernel
raspberry controller
+1 on raspberry pi
I too would love to see this being used as controller. I'm waiting for mine, 9 weeks to go.
I don't mean to burst your bubble but LinuxCNC on the Raspberry may indeed be "Pi in the sky" for the a while. I have been following Jon Elson's (of Pico Systems) progress on adapting the Beagleboard (a very similar platform) for the last 2 years. The first task was to emulate a parallel port which he was able to accomplish. The real-time kernel was the deal breaker. He's been waiting on a kernel guru in Germany to complete an RTAI kernel for the ARM processor with no results to date.
I would love it if we could use ARM processors for LinuxCNC and I'm hoping now that there are a couple of popular platforms generating a lot of activity that some genius will crack the realtime nut. In the meantime, there is a compact and relatively inexpensive option using some of the Intel mini-itx boards.
The miniemc2 project looks interesting. This is the first I've heard of it. Just reading through the website quickly, it appears that the project has a way to go yet but it's encouraging to see someone working on it. It also appears that he isn't actually using a true RT kernel but some "black magic" with interrupts
I'm sure we're not far from some really inexpensive and compact controllers very soon. I envision something like an ARM processor piggybacked on a Gecko G540 controlled by an Android phone. Oh, and while we're at it, it should be running a machine with interchangeable milling, extruding and laser heads.
Well, I can't really comment since I don't know Jon Elson's area of competence - emulating a parallel port for example is AFAIK totally unnecessary (it's another "no PIOs" workaround from PC land just like USB), so I don't know why he would spend any time on that.
Jon Elson, of Pico Systems, maker and designer of motion control hardware:
Pico Systems :
He does know what he's doing.
Mark
RasPiComm
I made an extension board with focus on stepper control, should go to production soon. It exposes an RS485 port, where I connected a Steprocker board (3-axis stepper controller with 256-microstep resolution).
RasPiComm – a Raspberry Pi piggyback board « Daniel Amesberger
I made the schematics open-source.
Daniel
So, my background is in embedded kernel work... specifically on ARM. I might be willing to hack on RTAI for ARM if I could trade my time for motion control hardware. Boards, servos, or most preferably linear rails and ground ball screws. Maybe even if it meant someone would keep an eye out for me for good deals on ball screws/linear rails... I know some places with high precision grinders trash their C0/C1/C2 ball screws on a regular schedule to make sure the machines are up to spec. Not looking for anything up front... I do love kernel hacking but could use some help with my own projects as well
The parallel port emulation is to retain compatibility with his line of motion control boards.
Hi
I like your idea.
So what Kind of projects you are thinking of ? PCB milling ? 3Axis Router wood alu or steel
A pick and place Maschine.
i refurbish an proxxon MF 70 to ballbearings threads
So give me an hint what is on your mind.
Cu
Thomas
I'm working on a small epoxy granite machine for making molds for small planetary gearboxes and for directly milling microwave waveguides in naval brass. The end machine I want to hold tenths over 6 inches. Appropriate components might be crossed roller slides, 50 Krpm NSK spindles, C2/C1 ballscrews, heidenhain encoders. Again, I understand that these things are really expensive, but there's a huge network of people here and I'm really just looking to be connected to the people who are trying to get rid of these things for reasonable prices. I've gotten lots out of RTAI for various things and I would like to just give back, but I'd appreciate some help here as well
Important part is getting the realtime kernel sorted.....
I have been messing around with linuxcnc on the RPI for almost 2 months now, I have not got far with the realtime kernel but the rest of it looks fairly simple to do.
I have the system running steppers without realtime but it seems to suck speedwise, I hope everything will be fine when linuxcnc is compiled for real time kernel.
If a few more people can sort out all the requirements for cross compiling a decent realtime kernel then maybe things will all start working with a combined effort. I think maybe my current problems are with my build environment and getting the right compiler flags and .config, I have not yet been able to get a real time kernel to fully boot (though I have only made 2 attempts so far, I hope to start looking at realtime again this weekend).
I have been posting mostly on the raspberry pi forum but also recently made a post on the linuxcnc forum, and there is a video on youtube showing it running.
Check below:
Raspberry Pi • View topic - Real-time linux kernel
EMC2 running on Raspberry Pi? - LinuxCNC Support Forum
Raspberry Pi • View topic - LinuxCNC (Emc2) How to compile and get it working...........
There are a few other threads on the raspberry pi forum that are relevant but I'm sure you can search them yourselves.
If anyone in the US is looking to buy one, they are in stock now, both the Model B board only as well as kits that include a case or other accessories, at MCM Electronics:
MCM Electronics | Raspberry Pi at MCM Electronics
I got a package from MCM Electronics today - I had ordered the complete kit which includes the R Pi board, a Bud cabinet, wall-wart power supply, USB mouse and keyboard, and SD card with OS. When I placed the order, it was supposedly "in stock".
Guess what was missing from the package - the R Pi board and the keyboard. Upon further investigation, the shipping list says that both are "back-ordered".
So, I guess that "in stock" representations by MCM Electronics can not be trusted.
