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EMC2 running on Raspberry Pi?
I use .25 ms over SSH and have no problems with the buttons, it is slow for activities that consume CPU and will not maintain the minimum time 2mS for signal of steps over GPIO Direct.
It is the opposite of its

I still have my Xenomai image on google drive if you want to test with Xenomai on this pass me the email for sharing.
Best Regards
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mungkie wrote: I found that for some reason I could not drive motors at more than 1500rpm (according to my rpm meter) this would be a pulse frequency of 5000 pps, 25us should allow 20000ppst.
This could be a physical limit. 1500rpm is very fast for a stepper motor.
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andypugh wrote:
mungkie wrote: I found that for some reason I could not drive motors at more than 1500rpm (according to my rpm meter) this would be a pulse frequency of 5000 pps, 25us should allow 20000ppst.
This could be a physical limit. 1500rpm is very fast for a stepper motor.
Its not a physical limit unless its a driver physical limit where the driver stops sending pulses higher than a given frequency, as far as I am aware normally driver will continue sending pulses but motor will stall but it is still possible to tell that the step frequency is increasing as the vibrations can be heard increasing in pitch.
The problem I am finding is that the motors reach a maximum speed and do not go beyond that speed or stall and give any higher pitched sound regardless of the feed or jog override set in axis, I probably have not setup the hal config properly.
I will look into it further once I have fixed the usb input lockups.
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I have been messing about with kernel configs and updates and it looks like the input lockups could be fixed, so I am guessing it could be only 100 hours programming and debugging to get the driver polished with gpio input and output.
I just need to do some final tests on kernel performance and latency under load so I am sure that its possible to get decent performance, then I will start a kickstarter project to fund the final development of the gpio driver.
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Best Regards
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My idea is that there are probably too few people that would support development, but if I could create a full package of parts to create cnc motors and drivers with interface that any beginner could make in a few hours and would run a sherline or 3dprinter at cheap ~£75 cost, maybe there would be enough people interested.
Unfortunately getting components at a reasonable cost means higher volume bulk purchase. So I think it probably unlikely that would be funded either but I am going to try a kickstarter for it anyways.
I show below the assembly/setup of the electronics I have sourced, the motors and power supply I have not finalised with suppliers yet.
If anyone is interested in further information read the information on the youtube video page.
Video shown below:
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I am not trying to be a buzzkill, but when you can use a ready-to-go version of LinuxCNC on the stock beaglebone black, which is noticeably faster than the Pi, why even bother?mungkie wrote: I have been thinking about trying to finish off the drivers and creating a distro for linuxcnc on the rpi but cannot workout how it would be possible to fund it....
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mungkie wrote: I have been thinking about trying to finish off the drivers and creating a distro for linuxcnc on the rpi but cannot workout how it would be possible to fund it.
One way would be to do it and simply not fund it. ie just treat it as a hobby, and give away the results. Like cross-stitch, except nobody wants cross-stitch.
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For sample,
I am walking with ODROID-U3 + LinuxCNC + RT Kernel as a hobby. I'm using version 1 without SPI and I can say that is very close to a conventional computer (around 1.2GB of memory with full load of CPU quadr-core during a convertion: 20 seconds on Odroid and 15 minutes on RPI to convert image to Gcode) At the moment I just need hal SPI driver (the maintainer of hardkernel / ODROID released version 2 of ODROID-U3 with SPI pins, they are very understandable, I'm hoping my buy).
I'm not saying to change the board, just my point of view across your comment.
Best Regards Mungkie
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check it cubieboard.org/2014/05/04/cubietech-will...performance-mini-pc/
www.flickr.com/photos/125001602@N03/sets/72157645370517326/
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