Remora - ethernet NVEM / EC300 / EC500 cnc board

If this feature and a higher step rate could be achieved it would be fantastic. Iv just ordered one for about 90 euro from China to have a play around with.

Middle speed counting is possible for the NVEM. High speed counting - is not.

Is it possible to use ec500 for 5 axis simultaneously cnc ?
WIth ads-a3 delta servos which support rs485 and can open

Thank you, I could get my NOVUSUM-NVEM working at 80khz , but not more than that.
we are waiting anxiously for the new firmware with DMA..

MX_Master wrote:

NVEM developers made a hardware planning mistake, so we can't output pulses directly using STM's timers. But yea, we can use timers + DMA to write data to the GPIO BSRR registers. One problem here - we can use only timer 1 and 8 to do the trick because only those timers has a transfer requests for the DMA2 controller. DMA1 controller has no access to the GPIO BSRR registers. So after a first look we have just 2 stepdir channels for the high speed pulses generation. After second look I found out that we can use timer 1 and 8 for the other stepdir channels too. To do that we must use other timers to generate softly (inside IRQ handler) unused DMA transfer requests for the timer 1 and 8. As a pulses counter we using DMA transfer counter.

And now we got two methods:
FAST (timer1,8 -> DMA2 request -> DMA2 stream -> GPIO BSRR) - up to 1 MHz of pulses;
SLOW (timer3,4,6,7 -> IRQ handler -> DMA2 request -> DMA2 stream -> GPIO BSRR) - up to 400 KHz of pulses.

I can't show the sources because I'm using some parts of the code for the business. But this short description will help to understand the tricks.

MX_master, thanks for the inspiration! Some success but lots of work still to do. I'm sure I can have fixed 500kHz pulses on all axes... Currently on 500kHz on 4 axes with 250khz on the last two but this is due to some timer cascading I need to sort out.

I only chose 500kHz as this is the name plate rate for the EC500, max step rate will really come down to the time needed to calculate the step pattern buffers.

My implementation will also have a DDS step generator for each axis and all going well step length and direction setup and hold parameters. But I will test without to start.

And this is achieved with only 2 timers for the 12 outputs across the two GPIO ports.. may need a third time to solve the slow output on Port A.