Remora - ethernet NVEM cnc board

For me who live in Brazil, unfortunately the purchase of a Nvem does not pay and for this reason I will make my own board because it will be much cheaper, I am also with the project using esp32 to make it even cheaper to manufacture.

For 2 weeks

My work on DMA step generation may have come to a brick wall. Using DMA to do the port manipulation is working great, generating a step buffer using DDS works, BUT not fast enough to be able to do it in a single servo thread . Having to do 6000 DDS calculations in a servo period may not be achievable with my current approach.

So, I've pushed my WIP to the DMAstepgen branch for people to see. Any thoughts on how we can generate the required step buffers within a servo period are greatly appreciated. Removing all of the step timing options will reduce the execution time but if it's enough I'm not sure....

I was nearly ready to throw away the idea of using DMA and a step pattern buffer, but after thinking on the problem I might try one more approach.

The LinuxCNC step generator which Remora is based on basically checks to see if a step should be generated at each base thread execution. I was stepping through each element of the step buffer and did this check.

If we turn this around and say, at which positions in the buffer should we step at? This is far less calculations, especially at low step frequencies. 

This would reduce the number of max iterations down to 3000 (500 for each of the 6 axes) and only when all are commanded at 500 khz. And the calculation is a more simple addition and division. Simulating this in Excel shows a similar output as the DDS approach, with maybe a little more jitter at high step rates. Nothing to concerning.

I won't be able to get to coding this for a week or so, but fingers crossed we can get this within a servo period, worst case would be to find the highest step frequency that can be achieved.

Today, 18 august, i received the controller. Looks realy good

You got in quick enough, mine is still on order. They pulled everything to re manufacturer. I'll post the pics when I get mine. To see what they changed .

I received my EC500 and NVMPG yesterday. Firmware uploaded and running so far apparently. However, when the handwheel is connected, Linuxcnc goes into estop and I get the following error. The EC500 must then be switched off and restarted, since Linuxcnc no longer comes out of the estop. does anyone have an idea or is remora not ready yet?

Do you have the switch on the ec500 on std or nv?

Iff posible also try with a std mpg.

CBollweg wrote:

I received my EC500 and NVMPG yesterday. Firmware uploaded and running so far apparently. However, when the handwheel is connected, Linuxcnc goes into estop and I get the following error. The EC500 must then be switched off and restarted, since Linuxcnc no longer comes out of the estop. does anyone have an idea or is remora not ready yet?

Hi, I've not got the NVMPG running with my EC500 as the serial communication on my board does not seem to work correctly at high speed. Can you share a picture of your board? If it's similar to the NVEM then we will be close to getting it working. When you say LinuxCNC goes into estop, when does this occur? When you try to jog?

 

on nv