BeagleBone Black and PRU Driver for Linuxcnc? Or switch to RP-4 / Mesa?

Hello World,

I have a lathe running Machinekit on a BeagleBone Black using the PRU for stepper control, spindle feedback and spindle speed PWM. I am tempted to update this setup to get support for G71. Now I consider Machinekit effectively dead and would like to move this over to Linuxcnc.

I'm now trying to decide on the direction to take:
- Try to port the PRU driver and hal_bb_gpio to Linuxcnc and compile Linuxcnc for this board. This tries to get around changing anything on the hardware side. This would be a useful direction if the code could be contributed back to Linuxcnc. I recall that there was some tension and that was why Machinekit was forked from Linuxcnc. In this light I wonder if this direction is feasible at all (with limited effort)
- Replace the BBB with a Mesa card based setup (e.g. Rasberry PI 4 + Ethernet based card)

Does somebody has advice for me here?
Malte

another option if you want to use a RPI 4 is the Remora project
github.com/scottalford75/Remora
remora-docs.readthedocs.io/en/latest/intro/intro.html

Give it a read and see if it meets your expectations.

I have had great luck with this project and the creator is very actively and helpful.

It would certainly be a great addition to LinuxCNC to have full PRU support,
but I have no idea how big a project this is.

Thanks for the feedback.
I did see the Remora project but I will go for a Mesa card in case I rebuild the controller. They're not expensive enough considering the amount of work involved and will be more future proof

PCW wrote:

It would certainly be a great addition to LinuxCNC to have full PRU support,
but I have no idea how big a project this is.
 

I thought Jeff had helped John K get a linuxcnc version running on the beagle bone green - just for John's project.
I might be wrong - it was a long time ago.

Chris

Since we are talking about beaglebone
github.com/SebKuzminsky/hostmot2-firmware-beaglebone
This is different than the machinekit beaglebone implementation correct? 
Its dedicated pru firmware , and the machinekit is more of a software stepgen/pru driver?
Or are they the same thing?

Seb is a linuxcnc developer so I would guess that's for linuxcnc not MK.

Not sure what the difference is though.
I have a beaglebone black somewhere - it might be nice to make it do something..

Yeah, Ive seen his name come up in a lot of things, but not the linuxcnc beaglebone drivers,
so I was wondering if his work is the same as linuxcnc beaglebone drivers,or if its the same as the machinekit bbb drivers or if both the linuxcnc/machinekit bbb drivers are the same, is this one an improved version with higher steprates as this is pru firmware? I only ask because I dont see any reference to seb in any of the bb drivers, and from my reading/understanding of the topic the current drivers didnt make full use of the pru. I am curious as it seems like a different process compared to the other beaglebone implementations.

github.com/LinuxCNC/linuxcnc/blob/master...rivers/hal_bb_gpio.c
github.com/LinuxCNC/linuxcnc/blob/master...rs/beaglebone_gpio.h

github.com/PocketNC/machinekit/tree/expa...vers/hal_pru_generic
github.com/PocketNC/machinekit/blob/expa...b_gpio/hal_bb_gpio.c
github.com/machinekit/machinekit/tree/ma...vers/hal_pru_generic

the beaglebone is a nice board that seems ideal for this type of application, and the limitations holding it back before like slow graphics can probably be solved by it now having a hardware graphics driver, and appears to support qt. Im just having a hard time getting it all working because Im not to good with computers.

Allwincnc is another. It uses some allwinner ARM soc's and their integrated micros to perform as well or better than BBB with its PRU's.

allwincnc.github.io/index.html

forum.linuxcnc.org/18-computer/39037-lin...-orange-pi-allwincnc

If only doing one machine and willing to spend couple hundred for a Mesa setup it's a good way to go and having long running commercial support can be a good thing.

I have already converted 2 machines to LinuxCNC/Remora and have a 3rd to do. So with each machine costing under $100 for the conversion is roughly $300 for 3 vs $1000 for the three and I already had one compatible controller board in one of the machines so it was just a firmware and config.txt file change on a uSD card and some tweaking of the hal and ini files.

I almost went for Mesa but then found Remora and its developer.