Remora - Rpi Software Stepping Using External Microcontroller via SPI

Remora is a free, opensource LinuxCNC component and Programmable Realtime Unit (PRU) firmware to allow LPC17xx micro-controller “Smoothieboard” compatible controller boards to be used in conjunction with a Raspberry Pi to implement a LinuxCNC based CNC controller.

remora-docs.readthedocs.io/en/latest/index.html

github.com/scottalford75/Remora

image missing https://remora-docs.readthedocs.io/en/latest/_images/rpi+board-new.png

"Some instability in SPI communication needs to be resolved."

Maybe we can help him finish the firmware.

There are $25 clones of the smoothieboard available from China. This project uses mBed for the firmware so it should be transportable to many other ARM microcontrollers and boards.

Hi Bari,

I see you've found Remora! The SPI instability is with the Mbed OS6 version. The precompile firmware is the OS5 version which is stable and running real machines!

There are a few people using Remora and helping with the development of additional features.

Trinamic stepper drivers currently being tested and integrated.

Yes. I have been looking at other microcontrollers to possibly port this to since the LPC1768 has a 6-12 month lead time. Many of the LPC1768 boards like the smoothie are also out of stock and their clones are using fake LPC17xx parts.

Do you want to add this as a distributed LinuxCNC driver?

Hi Scotta,
I think it would be awesome for this to be included with linux cnc.
This plus the RPI4 is a great setup.
Just cant wait till more people hear about it and try it out.

With the updated encoder support i am hoping to be able to get my machine running with the ability to do rigid tapping and hopefully a pid feedback to keep spindle at speed when cutting.

Hi Andy,

Having it included in the LinuxCNC distro would make it easier for people to install. It would also mean that changes to the component would need to be phased and more controlled.

Features on the firmware side are being added as different people want to use Remora in different ways.

Scott

Porting to the STM32 would be great but would need some work. The heart of Remora is the DMA communication and threads, both of which are tightly linked to the LPC1768 at the moment. Not impossible to port but time consuming.

Was not aware of the fake LPC parts getting around. I just picked up another controller board quite quickly from China. How to tell a fake chip?

But it works ok.

Hi Aaroncnc, it was great to work with you on the updated encoder support and great to hear the you got rigid tapping operational!

I still need to investigate the hardware QEI module so you can do high speed counting. Now that the TMC2209 is available in the testing branch I can look at this .

scotta wrote: Having it included in the LinuxCNC distro would make it easier for people to install. It would also mean that changes to the component would need to be phased and more controlled.

I can't decide if you are saying it is a good idea or a bad idea.

Hi Andy,

I think it's a great idea!

The downside is on my side. I won't be able to play with the code as freely.