Remora - ethernet NVEM cnc board

Great work!

I am loving these updates.

So with the use of ethernet vs just spi will we be able to reach high step rates?

scotta wrote:

I'm contemplating doing this version of Remora in STM32CubeIDE rather than Mbed Studio as this will be specific to the NVEM board with the STM32F207.

Thoughts?

I dont really know shit, but heres my 2 cents/sense

mbed studio seems a lot more .....noobie friendly to get going initially, but appears to be limited in support for anything non official mbed board, and debugging without having official mbed board seems rather difficult to do. cubeide initially seems rather complicated to setup, but it seems more useful for stm based boards and appears to have a better debug environment (im hoping) because setting up and useing an ocd/server is proving challenging.

What is the motivation for the change? Is it related to ethernet or other?

Primary reason is related to the ethernet implementation. In Mbed they have wrapped up the LwIP in a full API hierarchy which needs the RTOS to function. In STM32CubeIDE it's running fine in bare-metal polling mode.

I've also found the debug abilities to be useful. In Mbed it's adding printf's everywhere but being able to add breakpoints and step through the execution and interrogate values was really useful in getting the ethernet running.

Aaroncnc wrote:

Great work!

I am loving these updates.

So with the use of ethernet vs just spi will we be able to reach high step rates?

The communication is independent of the step rate, so no. But I'm still playing with doubling the current max step rate.

Just a quick comment about cubeide. If you use those libraries for your project I believe it is a relatively smaller lift to move to platformio which will open things up to a wider group of developers and hobbyists.  Just a thought for the future.  I think moving to cubeide would be a benefit over mbed.

Just my 2 cents
i used these board often for building plasmas and routers with Mach3 in the past, and it is cheap and very stable solution with ethernet interface. I have no experience in programming but my electronic knowledge and testing equipment can give you more information about testing the product if it needs you
keep tracking these thread 

drewnabobber wrote:

Just a quick comment about cubeide. If you use those libraries for your project I believe it is a relatively smaller lift to move to platformio which will open things up to a wider group of developers and hobbyists.  Just a thought for the future.  I think moving to cubeide would be a benefit over mbed.

I've just had a look at the stm32cube framework and yes it looks like an easy uplift to PlatformIO. PlatformIO was the original development platform for the LPC1768 version of Remora until they broke the build system. That prompted the move to MBed. 

Remora does not use many of the MBed API's, but the ones used would need to be adapted to use STM32 HAL, which was already done for pin access etc.

Remora would have to drop support for NXP chips though, which in the current chip shortage environment would not cause an issue as I have not seen one new 3D printer controller board come out with an LPC chip.

Pro_El wrote:

Just my 2 cents
i used these board often for building plasmas and routers with Mach3 in the past, and it is cheap and very stable solution with ethernet interface. I have no experience in programming but my electronic knowledge and testing equipment can give you more information about testing the product if it needs you
keep tracking these thread 

This is great news. Your experience with Mach3 and these boards will come in handy. Especially when it comes to how the functionality of some of the ports is used. The adjust port is one that comes to mind. We'd need to implement similar / same functionality for LinuxCNC.

Remora-NVEM is getting closer to turning a motor. The threads are up and running at expected frequency. This was a bit of a challenge and where debugging capability has really useful. 

STM32Cube appears not to move interrupt vectors to RAM like MBed. This took some figuring out as the MCU crashes as the program pointer headed off to an unexpected memory address. I'll need to investigate this further as a RAM vector table is needed when using a bootloader.

It was really pleasing to see that the STM32F2 uses the same HAL has the STM32F1 so the code could be dropped in and up and running super quick. 

Next step, getting the Stepgen module up and running and spinning some motors

 

With the threads running it was straight forward to get the step generators setup and the Remora-NVEM is alive! First tests are great. Still a lot of code clean-up to do and enable all of the other features of the board. But it's running!