Remora - ethernet NVEM cnc board

I'll get them on their way tomorrow, we are in a regional area, I am pretty sure they still use Bunyip's to get the mail out to the larger cities, but with a bit of luck they will get to you next week.

Would two units be enough? I have four I can send if needed, can't see myself needing them anytime soon.

Allwinner H5 and stm32f405 on the same board for $50-80 with/wo wifi, SD-card etc

www.aliexpress.us/item/3256803350581362.html

Don't mean to hijack this thread. just wanted it to be seen.

Questions: How is the H5 connected to the stm32, SPI, or?

Will need a small board to convert the sockets for the stepper drivers to screw connectors for connecting external stepper drives >3A. Will need a good Linux image and u-boot so it doesn't have the same issues as the OpiCNC project. Minimal Remora work for the stm32 on board.

A real quick look at the schematic and it looks like an SPI and uart connection between the two. If there's an Linux image for the H5 and an SPI driver, then Remora would be a potential candidate.

Well my parcel arrived from cncboy.... they pulled the old switcharoo and sent me some lovely USB 2.0 cables from the early 2000's. Absolute bargain at $240.00

They claim that the boards are being made now and will be finished in two days... who knows.

"If there's an Linux image for the H5 and an SPI driver, then Remora would be a potential candidate. "

That is not a problem if the board is actually worth using and readily available.

Scotta:  Where did you find a schematic?   Link please.

NVM, found it:  raw.githubusercontent.com/Mellow-3D/Fly-...ni-V2_2022-04-14.pdf

Hey there,

my attempts to reproduce the NVEM-linuxcnc configuration ends up with an error message, saying there would be a positioning error for the motors.
Error message in the terminal says "emc/task/taskintf.cc 942 : error on joint 0" followed by the command number.

I've been looking through the HAL-files but couldn't find a thing.
The board gets detected and i can see the different I/O-pins. Also i am able to observe any inputsignals trough this pins.

My Linuxcnc is running on an Desktop in version 2.8.4. [Debian 10 (New installation)] all configurations for the board and L-cnc made like in Scott's video.

Any idea how to solve this ?  

 

First and most important to take a look at your joint follow error in halshow, halmeter or halscope.

I assume that the error happens when you try to jog. Maybe your step rate (scale) is higher than then configured PRU frequency?
In this case, the PRU is not able to emit steps that fast.

Other possibility is that you did not configured the joint feedback at all. In this case, the position feedback stays at 0 and therefore you get the error.

There is a small probability we can help without knowing your configuration, version and when the error happens.

@Scotta
I am using Remora for a bench prototype with the NVEM v2 board with 6 axis and 3 motors. I am using the 1.0.0 release.

I discovered the following strange behavior of the driver card:
0. Start LinuxCNC
1. Enable drivers
2. Jog a little bit
3. Power off card (disconnect 24V)
4. Power on card
5. Unset EStop
Now the commanded position and the position feedback from Remora differs (about 0.1 - 0.05mm).
This is not corrected, because the EStop is active.

Now, if I enable the drivers, the motor moves a little bit. LinuxCNC corrects the position error.

What could be the reasons for this? Why does the position feedback change after power on of the card?
Are maybe the PID values wrong?

I hope I described the problem to be understandable ( ). Just let me know if you need further information.