LinuxCNC-RIO - RealtimeIO for LinuxCNC based on FPGA (ICE40 / ECP5)

I am chasing a weird issue. I reduced the microsteps on my machine from 16 to 2. That changed the scale from 540 to 80 on x and y and 800 to 100 on z.

Now my machine is not homing anymore. I get this error: home switch inactive before backoff.

Here is what I have done so far. 
1. Changed the Microsteps from 16 to 2. And just changed the rio.ini file. 
2. Machine started homing in the right speed settings, but threw the above error.
3. I changed back to 16 microsteps and the machine is homing fine. Changed back to 2 microsteps. 
4. I tried to reducde the home search velocity, but no change. 
5. I increased the home search speed and the machine is not showing an error, but is not homing. It does it homing cycle, but then continued to go in slow speed. I believe towards home, but not sure.  

I tried to reduce the mircsteps from 16 to 4 and played around with speeds for homeing. I am able to home. This is now discovering the real issue.

When I manually move an axis of the machine sometime it stops. And sometimes it continues to move slowly. For example in X I see in the display that X is 0.00000 and jumps around to 0.006252 or so. I believe this has happened already and has something to do with the F error or F min or so.

Well, it's all working again. I increased the deadband from 0.001 to 0.01. Now it's also working on the old speed settings and with 2 microsteps.

Seems like there is still one question remaining:

What would be the ideal set up for a stepper motor with 5mm pitch ball screw and 1.8deg/step paird with a DM332T which can't go below 2 microsteps. Is there a setting which is ideal for this set up where linuxcnc positioned the machine on exactly a step/microstep?

I need some help here again. I am having a weird issue with my machine. I first thought it has nothing to do with Riocore, but now I am not so sure anymore.

Posted here: forum.linuxcnc.org/12-milling/57122-mach...-programm-repeatable

Oliver or someone with experience, could you explain a bit more what the settings in the Stepper dialog under Step mean?

The Step signal for my machine is inverted. I tried to remove the inversion from the step signal, but than the Stepper don´t move at all. Does that make sense??

# The Step signal for my machine is inverted. I tried to remove the inversion from the step signal, but than the Stepper don´t move at all. Does that make sense??

please check your Opto-Outputs, perhaps they are too slow for the short pulses. ?!?!

EDIT: and please add you config

Some Testest with the Mesa 7c81 and 400W Servos:

www.youtube.com/shorts/KLijHrYiQXw

Board: eusurplus.com/index.php?route=product/product&product_id=131 + 5Axis-BOB
Servos: www.amazon.de/dp/B0DM5V6BZ2
Spindle: Huanyang VFD via Modbus

Hi meister,

Really cool project! I was thinking about combining FPGA support and  LinuxCNC on an  Ultra96  board (Xilinx/AMD Ultrascale device, 4x ARM64 cores and FPGA on the same chip) for years, but had no clue how the HAL messaging works. But with your UDP example as a base it was really easy! Below is a pic of the demo system, which is the Ultra96 itself, a simple self made interface board and the CNC Shield v3.0 at the top. And of course a video . :-)When I was done I saw you had added and experimental "axi" plugin and it looks like you had the same idea like me, but it did not work for me. In case you are interested, I could send my versions of the verilog and and c-code portion and maybe you could add it in a later version of your code generation magic.

Thomas 

 

Wow, that's really cool. Unfortunately, I can't afford the UltraScale's ;(

I once tried using a miner board (S9) and wanted to use the ARM part only as an Ethernet bridge, but I ran into a few difficulties and didn't continue with it for the time being.

But what you've done there is amazing

LinuxCNC-RIO - Mesa 7c81 - 7.14 KHz loop - 4x400W AC-Servos

www.youtube.com/shorts/DAJdqbjLjDQ

Mesa 7c81 over w5500 - Ethernet on RPI4 with qtdragon_hd (3.3Khz loop)

www.youtube.com/shorts/agf3f0MJxv4