Remora - Rpi Software Stepping Using External Microcontroller via SPI

Cncninja

Its something i have been thinking about.
If i could get more time i want to create a standard image with a config setup for the basic use cases. mill, 3d printer, laser

the idea would be someone could just download the rpi4 image and put it on a sd card and copy a file onto the sd card of the skr and be off to the races.
No installing or anything.

I have a STM32F407VGT6, I want now try the remora STM32 code.

The library looks old (stm32plus) and i'm using this repo :
github.com/mhelmarc/Remora-STM32
and this library :
github.com/mhelmarc/stm32plus/tree/musings
 

It is all in Beta. You are free to update your own branch.

gtt38 wrote:

The library looks old (stm32plus) and i'm using this repo :
github.com/mhelmarc/Remora-STM32
and this library :
github.com/mhelmarc/stm32plus/tree/musings

 
You're going to have to wait for Scott's port to Mbed-Os .
It might be a while, he just mentioned his new board is on it's way.

The library is as old as your mcu but it's pretty complete.
I have diverge from making a PRU equivalent of Remora.
The library is template heavy, configuration can not be done
at runtime, well you could if you try to do something like what
I did with the GPIOs, but it won't make sense.  It defeat the purpose
of using a library if you're going to rewrite most of it.

well let's do it, what do you have so far and where can i add to it?

@scotta
Hello, thanks for all your work.

I am not from a 3d printing background, and I read
"I've had no need to push the frequency up as possible speed ~200mm/sec for a
3D printer setup is more than adequate."

What is the typical 3D printing pitch, gearing, max rpm, stepsize?
I am sure if i google that i will get a lot of differing answers,
but you have a vision i would like to understand.

The STM port sounds good, as the MKS and SKR boards seem unobtainable.

Thanks TomP

edit
oh ( tomp fiddles with calculator )...
i suppose its a 4mm pitch with 1/4 microsteps and 40khz pulse rate, so 5um stepsize
so the only thing left to ask is
what accelerationis typical? I know its machine dependant but at some low value it may bother printing.

thx tomp

@cakeslob @mhel
did you ever get Xmotion to work?
If possible, please tell how
a non-x framebuffer solution removes a load from cpu.
I failed to get it to work, many times
thx
tomp

I actually haven't touch it yet, I just had a looked at it.
a few months ago. It's using LVGL gui toolkit, I had a
chance to use that toolkit when I made a simple
coin operated wifi for my nephew, but that's all.
Maybe you're better off asking here: forum.linuxcnc.org/41-guis/35225-new-gui...dded-systems?start=0 that's where I found it.

Cncninja wrote:

well let's do it, what do you have so far and where can i add to it?
 

Do you have the hardware already?
I can't really do much with my setup yet.

  Most 3D printer board manufacturers don’t use the right pin mapping of the chip. The chip is using software pwm to generate steps if the pin is not hardware pwm. I’m trying to use P2.0 to P2.5 for step generation with good results.
The step generation limitation could come from the SPI communication too slow maybe.