Mbed ethernet controler for LinuxCNC

Hi is there anybody out there that would be interested in helping me to fork of the rt-8p8c project to be able to run an Mbed to control a CNC machine, laser engraver, 3D printer, watercutter e.t.c.


Do you know the Remora project? It sounds similar, but is newer. It is also discussed in the LinuxCNC forum.

Hi Johannes,
Interesting solution but this solution seems to be running gcode from SD card and I want to control the machine in real time from linuxcnc through ethernet.
I also want to rework my parallell port bob design to be able to integrate more functionality.

Intention is to give me more knowledge and in the end share it in our comunity as a platform for others to use and continue to develop on.

I’ve been coding for awhile and only sheeted in objekt oriented programming.
However, I’m cuite good in PCB design and 3d-cad.

So please join in everyone that is interested in working on something that can be benefitial for a lot of people.


Hi Johan,
no, the idea is the same, to use LinuxCNC as host, the SDC is only for reading runtime configuration.
This Remora version uses a Raspberry Pi and SPI with DMA as fast connection to the 3D printer board. Scott was working on using the newer SKR3 Board with STM32H743. I have started to help with my SDIO SD card lib, but it is difficult with DMA and cache issues. You need 32 byte aligned memory, and compiler support for this is poor. GCC can do it, ARMCC has no implementation for memalign or aligned_alloc. There is an issue with newer gcc versions which produces compile faults with bad newlib version numbers. And Mbed has a problem with memalign and heap statistics turned on. And now the poor ARM support for Mbed…
So I’m switching now to Jamies Mbed-CE version with better CMake and VSCode integration und try to fix some basics first, then I get back to the Remora project with H743. Ok, after I’ve finished my HeaterController, but is using also the H7 DMA stuff.

Hi Johannes,
The same, but not the same.
Remora project is running LinuxCNC on Raspberry and connects to control board via SPI bus and serial port for debug.

What I want to do is to create a control board with MBED incorporated which connects to LinuxCNC through MBED ethernet port.

What I have today is a limited parallel port break out board or BOB which limits the number of outputs/inputs, unless I attach another BOB.

The parallel port is or will be obsolete which makes it difficult whenever my computer needs to be updated.


yes, I get always confused by the versions, there is a Remora version vor Novusun NVEM and EC500 and these are using ethernet. But not Mbed, to get low latency, lwip is used there very direct.

Jsvens, hello allow me to try and clear some things up.

Remora NVEM versions are Ethernet but they are not MBED, I think there was some compatibility issues.

Remora main/develop branch, they a SPI based and uses MBED

Remora Ethernet branch of the same repo, is Ethernet based, and uses MBED, and uses WIZ5500 to do ethernet over spi. (I dont know what MBED ethernet port means)

Jojo, thank you for all your help, as always. I am glad you have not given up on the H743. I can handle some things, but once the DMA got involved, it became over my head. I hope the project continues to use MBED in the future, as it is easier to add boards this way, but I fear some of the bootloader/SD related problems will push the project away from MBED. When I say SD related issues, I dont mean SDIO, SDIO works beautifully. Perhaps I could ask the MBED community for assistance with my various issues.