LinuxCNC

[kinsa]

Here are the preliminary steps to create an updated Machinekit installation based on Raspbian Jessie for RPi v1 and v2:

• Download and install MINIBIAN
  The default un/pw is root/raspberry
• Install raspi-config

  Code: Select all

  apt-get update
  apt-get install -y raspi-config raspberrypi-bootloader
  

• Configure RPi

  Code: Select all

  raspi-config

  • Expand Filesystem
  • Overclock
  • reboot to apply changes
• Add Machinekit repo:

  Code: Select all

  apt-key adv --keyserver hkp://keys.gnupg.net --recv-key 43DDF224
  echo "deb http://deb.machinekit.io/debian raspbian main" > /etc/apt/sources.list.d/machinekit.list
  apt-get update
  

• Install RT-PREEMPT kernel
  • RPi1

    Code: Select all

    apt-get install -y linux-image-rpi-rt

  • RPi2

    Code: Select all

    apt-get install -y linux-image-rpi2-rt

• Update /boot/config.txt to use the new kernel
  • RPi1

    Code: Select all

    cd /boot
    echo kernel=$(ls kernel_rt*.img) >> config.txt
    echo device_tree=dtbs_rt/bcm2708-rpi-b-plus.dtb >> config.txt

    Use the corect dtb file for your board.
  • RPi2

    Code: Select all

    cd /boot
    echo kernel=$(ls kernel_rt*.img) >> config.txt
    echo device_tree=dtbs_rt/bcm2709-rpi-2-b.dtb >> config.txt

  Sample /boot/config.txt for RPi2

  Code: Select all

  root@minibian:~# cat /boot/config.txt
  gpu_mem=16
  arm_freq=1000
  core_freq=500
  sdram_freq=500
  over_voltage=2
  kernel=kernel-4.4.3-rt9-v7+.img
  device_tree= dtbs_rt/bcm2709-rpi-2-b.dtb

• Add the following parameters to /boot/cmdline.txt

  Code: Select all

  dwc_otg.fiq_enable=0 dwc_otg.fiq_fsm_enable=0 dwc_otg.nak_holdoff=0

  Sample /boot/cmdline.txt

  Code: Select all

  root@minibian:~# cat /boot/cmdline.txt
  dwc_otg.fiq_enable=0 dwc_otg.fiq_fsm_enable=0 dwc_otg.nak_holdoff=0 dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 elevator=deadline root=/dev/mmcblk0p2 rootfstype=ext4 fsck.repair=yes rootwait

• Install Machinekit

  Code: Select all

  apt-get install -y machinekit-dev machinekit-rt-preempt

• Install PICnc-v2 driver

  Code: Select all

  cd ~/
  wget https://github.com/kinsamanka/PICnc-V2/raw/master/HAL/picnc.{c,h}
  comp --compile picnc.c
  sudo cp picnc.so /usr/lib/linuxcnc/rt-preempt
  

• Install your favorite DE

  Code: Select all

  apt-get install lxde

  Replace lxde with whatever suits your fancy
• Add Machinekit user

  Code: Select all

  adduser mk

• Reboot

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  reboot

Note:
MINIBIAN was chosen to keep the installation size small. Standard raspbian image can also be used, just omit the DE installation step.

The rt-preempt kernels are still considered beta, tests are needed to see if this is suitable for Machinekit.

updates: Added RPi2 kernel

[kinsa]

Hi,

I found an article about experimental hardware accelerated OpenGL driver for Raspberry Pi.
http://hexus.net/tech/news/graphics/904 ... l-support/

I want to ask, now I using image RPi2-machinekit-1.0 and there is low performance of LinuxCNC GUI on RasPi2. It is caused by software accelerated OpenGL or it is completely different problem? Big ngc files also makes GUI performance slower. Trajectory generation works without any problem.

Thanks,
Viktor

The axis UI is a resource hog. This is inherent to the design of the interface. You can try the mini UI and you'll see the difference.

With regards to big ngc files, the preview window actually loads the whole ngc file to generate the previews. Turn off the preview and the performance will improve.

[mung]

Very cool that a new version of linuxcnc/machinekit is available, I think the xenomai kernel maybe more responsive when using axis gui, is there an ETA for when a xenomai version maybe available?

Also will 64bit be available for real time kernels?

[kinsa]

Unless someone ports xenomai to run on the latest kernels, there will be none

64 bit is too new. If someone has an developed an RT kernel for it I'll be glad to host it.

Cheers

[kinsa]

Updated instructions for RPi2.

Cheers

[VikTan]

What about run RPi2-machinekit-1.0.img run on RPi3? I tried it but it didn't boot. It's a problem of 64bit architecture?

[dega]

Kinsa,
there is a discrepancy on your steps: the /boot/config.txt should be

Code: Select all

cd /boot
echo kernel=$(ls kernel_rt*.img) >> config.txt
echo device_tree=dtbs_rt/bcm2709-rpi-2-b.dtb >> config.txt

instead of "echo dtoverlay=..."
in fact in the sample just below is correct; I tried the dtoverlay but the RPI would hang at boot

I am planning to use a RpiV2 with 3 x DQ542MA stepper drivers to control a cnc milling machine.
Do you have any suggestion on where to look for instructions on to use the GPIOs to control the motors directly? I just need the pulses there instead of a SPI communication with a Pic.

Thanks

[kinsa]

Are you using the latest bootloader?

I have not used the gpio directly. Maybe you can ask jam1 for his hal file as he was able to control steppers using gpio only.

[dega]

Are you using the latest bootloader?

I have not used the gpio directly. Maybe you can ask jam1 for his hal file as he was able to control steppers using gpio only.

I think so,
I downloaded the image 2016-03-12-jessie-minibian and then followed your instructions.

[kinsa]

Fixed the instructions, thanks!

Here's the example hal for driving the gpios: https://github.com/machinekit/machineki ... o_demo.hal

[dega]

Fixed the instructions, thanks!

Here's the example hal for driving the gpios: https://github.com/machinekit/machineki ... o_demo.hal

Thanks, I'll have a go.
If it works I'll post a guide on how to use GPIO as well, my milling machine is a MF70/CNC ready

[bfree]

Hello, All,
Perhaps, I am missing something but, so far, this new machinekit install is not usable fo me on a model B+ pi.
I installed using both cases, standard raspian and the minibian. The latter was more responsive, as expected, but still quite dreadful. Digging around the net I found this discussion that may account for the high CPU load: http://community.emlid.com/t/rt-kernel- ... cpu/1002/8 . Whatever the irq/33-dwc_otg stuff is, it is hungry for cycles (times 3); here is output from top:

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  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND                
 2563 pi        20   0  127144  72940  46532 R 32.1 14.8   0:46.45 axis                   
 2536 root      20   0   62680  59928  11952 S 22.2 12.1   0:35.76 rtapi:0                
   71 root     -51   0       0      0      0 S 13.2  0.0  12:21.89 irq/33-dwc_otg         
   73 root     -51   0       0      0      0 S 10.4  0.0  10:44.37 irq/33-dwc_otg_        
 2562 pi        20   0   24192  15152  12860 S  7.1  3.1   0:11.67 milltask               
   72 root     -51   0       0      0      0 S  5.5  0.0   5:56.48 irq/33-dwc_otg_        
 2590 root      20   0    5016   2564   2136 R  4.1  0.5   0:03.52 top 

I know axis is a hog but in the interest of comparing with the previous kernel, this is what was used and worked just fine on the same B+ unit.
Maybe, I am just missing something?
Have fun!
Bob

[kinsa]

Thanks for the feedback.

Looks like rt-preempt is not useable for older boards unless you slow down the usb speed by setting dwg_otg.speed=1.

I'll try to find an updated xenomai kernel and will post it soon.

Cheers.

[bfree]

Thank you for the tip. The dwg_otg.speed=1 setting improves things considerably, though still slower than previous.

Am having trouble getting machinekit operational with the rt-preempt image. The PICnc LED rate increases on loading the CNC program, as usual, but have not observed any motion and am getting following errors.
Does this image assume updated firmware in the PICnc?

Also, looking at machinekit status I see MAX_ACCELERATION numbers that are like 10^100; this, regardless of the values I have in the .ini file. Any thoughts on where these might be getting corrupted?

As always, thanks for the project, the good work and assistance.
Regards,
Bob

[kinsa]

I think the first gen RPi will only be useful with the xenomai kernel.

Unfortunately machinekit hasn't been ported to the latest xenomai version, 3.0, so we'll be stuck with the old kernel.

I'll try to update the xenomai kernel to include all the drivers but I don't have an old RPi at the moment so it will take a bit of time, maybe early next month.

Cheers

[bfree]

kinsa,
Has been a while since I compiled a kernel but I have been giving it a try - just for the re-education. In doing this I found the .config used for my current kernel does, indeed, have USB wireless enabled ad several devices (including one device I have) are compiled as modules. I proceeded to add apt sources for the firmware and driver (rt2800usb); now, the wireless is working!
Bottom line is that my wi-fi driver issue is resolved and there is no need to distract you from your other endeavours to create a new kernel/image on my behalf. But, I sure do appreciate the offer and support, anyway.
Thanks again,
Bob

[kinsa]

There's a known working 4.1 xenomai kernel for RPi 1. I just need to test it first before packaging

[dega]

Here is the hal_gpio driver to use directly the IO pins of the Raspberry Pi (V2 or V3 preferably),
to add it just follow the same procedure from Kinsa in viewtopic.php?p=920778#p920778 and instead of the PICnc-v2 driver just complie the 2 files in attach:

Code: Select all

comp --compile hal_gpio.c
cp hal_gpio.so /usr/lib/linuxcnc/rt-preempt

The file hal_gpio,c is based on https://github.com/machinekit/machineki ... hal_gpio.c but then I added the get_rpi_revision procedure and some other stuff from the BCM2835 library to control the pull up/down restistors as well.
For my application I load the module with:

Code: Select all

loadrt hal_gpio dir=15729632 pullUp=33652740

to get the pins in this configuration:
Pin 03, GPIO 02 set as Input, Pull OFF
Pin 05, GPIO 03 set as Input, Pull OFF
Pin 07, GPIO 04 set as Input, Pull Up
Pin 29, GPIO 05 set as Input, Pull OFF
Pin 31, GPIO 06 set as Input, Pull OFF
Pin 26, GPIO 07 set as Output
Pin 24, GPIO 08 set as Output
Pin 21, GPIO 09 set as Output
Pin 19, GPIO 10 set as Output
Pin 23, GPIO 11 set as Output
Pin 32, GPIO 12 set as Input, Pull OFF
Pin 33, GPIO 13 set as Input, Pull OFF
Pin 08, GPIO 14 set as Input, Pull OFF
Pin 10, GPIO 15 set as Input, Pull OFF
Pin 36, GPIO 16 set as Input, Pull OFF
Pin 11, GPIO 17 set as Input, Pull Up
Pin 12, GPIO 18 set as Input, Pull Up
Pin 35, GPIO 19 set as Input, Pull OFF
Pin 38, GPIO 20 set as Input, Pull OFF
Pin 40, GPIO 21 set as Input, Pull OFF
Pin 15, GPIO 22 set as Output
Pin 16, GPIO 23 set as Output
Pin 18, GPIO 24 set as Output
Pin 22, GPIO 25 set as Output
Pin 37, GPIO 26 set as Input, Pull OFF
Pin 13, GPIO 27 set as Input, Pull Up

[dega]

Now all the configuration files

MF70.rar

Configuration files

(4.54 KiB) Downloaded 560 times

if someone else is trying to do the same.
The driver board has just a BC 547 and a 5k6 resistor from the GPIO to the tranistor's base.

This is a short video of my setup: https://www.dropbox.com/s/y1u98e5fofup3qj/MF70.avi?dl=0

[enesterov]

Hello Everyone,

There is really great information in this thread! Thanks for all your efforts.

I've followed kinsa's and dega's instructions to get RPI 2 to run machinekit and I am almost there - the only things that is missing is that I would like to run my drivers in the "active low" mode. I've followed the the recommendations of the linuxcnc manual on how to invert sygnal

Code: Select all

setp hal_gpio.pin-22-out-invert 1

but machinekit won't start as it says that hal_gpio.pin-22-out-invert can not be found. I am using dega's driver from and would appreciate someone telling me what am I doing wrong.

[kinsa]

You can use the not component to invert a hal signal.

See here: http://linuxcnc.org/docs/2.5/html/hal/b ... .html#_not

[dinkata]

I installed it on Raspberry pi2 minibian and machinekit
viewtopic.php?f=37&t=33809&p=941129&hil ... nc#p941129
after that I installed gmoccapy_lcd7
http://machinekit-gmoccapy-lcd7.blogspo ... to-la.html
I am trying run configs ,gmooccapy opens ,but error mesage :
.......
Found an error!
The following information may be useful in troubleshooting:

Traceback (most recent call last):
File "/usr/bin/gmoccapy", line 4153, in <module>
app = gmoccapy()
File "/usr/bin/gmoccapy", line 241, in __init__
self._init_audio()
File "/usr/bin/gmoccapy", line 1038, in _init_audio
self.audio = player.Player()
File "/usr/lib/python2.7/dist-packages/gmoccapy/player.py", line 36, in __init__
self.player = gst.element_factory_make("playbin", "player")
ElementNotFoundError: playbin

.........
please help !
what it takes to work gmoccapy ?
GUI Axis work !

[jagspaul]

I have gone through the code of PICnc-V2 and tried to understand the logic of Step Pulse generator, but for me it is too difficult to understood.

Can anybody explain the logic of Step Pulse generator?
However I have some question as follows.

1) Why value of Step size (STEP_MASK) is too high i.e. (1L<<22) [2^22 = 4194304]
2) If STEP_MASK is set some low value (1L<<8) then what will happened .
3) position=stepgen_input.velocity
velocity value is received from LinuxCNC through SPI. What is the minimum & maximum value of velocity.
4) if velocity value too high then position will overflow within few cycle. How it will effect the Step Pulse generator?
5) How frequent LinuxCNC change velocity value & send through SPI.
6) How frequent LinuxCNC change stepwidth value & send through SPI.
7) How step pulse get stooped?

thanks & regards

/jags

[kinsa]

PICnc is a hardware implementation of the hal software stepgen component.

You can read the description here: http://linuxcnc.org/docs/html/hal/rtcomps.html#_stepgen

We're using the Step Type 0 mode.

Regards

[enesterov]

You can use the not component to invert a hal signal.

See here: http://linuxcnc.org/docs/2.5/html/hal/b ... .html#_not

Thanks kinsa, it looks like it worked. Still cranking through configuration but motors started to spin!