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ewlsey wrote:

Go easy on me. I tried to read through this whole thread, but there's a lot to digest. 

--snip--

I know it's not a "real" control, but it's pretty amazing they could get all that to work (along with g-code interpreter, etc) on an 8 bit AVR microcontroller. 

 

Just now I discovered:
GRBLHAL = 32 bit
GRBL = 8 bit
Thanks for bringing this up. A long time ago I read all about GRBL 8-bit and sort of gave up on it. Now I notice the main project is 32 bit. Now that seems worthwhile. Cheap 32-bit MCUs today pack some punch.

That said, I'll leave the S-curve talk for the pros.

Go easy on me. I tried to read through this whole thread, but there's a lot to digest. 

How does the current linuxcnc approach compare to how S curve acceleration is being done in GRBLHAL? 

I've tried to read the linuxcnc servo loop code, but it's pretty well impenetrable. 

However, GRBLHAL is very cleanly written and well commented. From what I can see, it has many features discussed here.

It has a backwards (and forwards) buffered trajectory planner with prescribed tangential acceleration. It has buffered segment interpolation. Both run outside the realtime loop, but the segment buffer is fast enough for feed overrides and holds to feel instantaneous. 

I know it's not a "real" control, but it's pretty amazing they could get all that to work (along with g-code interpreter, etc) on an 8 bit AVR microcontroller. 

The current HAL version offers jerk limited acceleration, though I have to say its utility is a bit questionable for industrial machines. I believe the GRBL equivalent of the "servo loop" only runs at 100Hz, so you would need really low jerk values to see an effect. But, the framework seems sound.

Thanks!
I looked it over and tried the simulation. It's looking good. Later this week I hope to find time to try it on my hardware.

rodw wrote:

Why can't you use more than one thread instead of a FGPA?

 

Thanks, I've been wondering too. I've been dreaming about kinematics using multiple realtime threads. Does anyone know whether/why it would not do?

Just asking specific questions on the forum may be enough to get you going.

 

TAKUYA wrote:

It seems like the drives arent going into OP right away. The delay is always different. Sometimes the DRO is instantly filled with the encoder read (but converted to axis position) values, sometimes it takes up to 10 seconds. 

 

Seems a bit unexpected to have up to 10 second delay before OP on ethercat. Is this a new config or was it previously working?

Does anything relavant show up in dmesg?
Once it finally populates the DRO, is everything working after that?

Also, unless I'm missing something, it's already sending back the raw count?

At this point, I've diverged quite a bit. I'm willing to do the work to separate it out, but do you want a big ugly PR or a stack of single-topic ones? I would start with a noop that makes indentation consistent (prefer 4 spaces, but 1 tab also works).

I'm also adding support for the new W55RP20 (docs.wiznet.io/Product/Chip/MCU/W55RP20/w55rp20-evb-pico), which has the W5500 on different GPIO and also conflicts with the example config.  I also bought a RP2350 version to play with.

I asked my imaganiry AI friend to take a look at it thusly:

"A friend of mine is trying to get a custom linuxcnc HAL component up and running and he's getting an odd runtime error of "hal:turret:1: character unknown ' '"

The documentation for hal stuff is here:http://linuxcnc.org/docs/html/hal/comp.html take a look and see if you see anything out of place."

While sending the comp file along.
The replies seem pretty reasonable:



I see two issues:

1. The actual error (line 1) — almost certainly smart quotes

The "character unknown ' '" error on line 1 means the halcompile lexer is hitting a byte it doesn't recognize. Line 1 has a doc string:

component turret "4-position pneumatic...";

Those " " quotes are probably Unicode smart/curly quotes (U+201C/U+201D) instead of plain ASCII double quotes (U+0022). Super common when the file was written or pasted through a rich text editor, Google Docs, macOS Notes, Word, etc.

Fix: Have him run this to check:

cat -A turret.comp | head -1

If he sees M-bM-^@M-^\ or any multi-byte sequences where the quotes are, that's the culprit. Replace all smart quotes with plain ASCII " quotes. Quick fix:

sed -i 's/[\xe2\x80\x9c\xe2\x80\x9d]/"/g' turret.comp

2. Secondary bug — FUNCTION name mismatch

He declared function _; (underscore = unnamed/default) but then used FUNCTION(turret) in the C section. Those have to match. Should be either:

FUNCTION(_) {

Or better yet since it's a single-function component, just skip the FUNCTION() wrapper entirely and put bare C after ;; — like the ddt example in the docs.

3. Minor — int diff inside switch/case

case 0:
...
int diff = target - position;

Declaring a variable inside a case without braces can choke some C standards. Wrap it:

case 0: {
...
int diff = target - position;
...
break;
}

The smart quotes are almost guaranteed to be the "character unknown" error. The FUNCTION mismatch will bite him right after he fixes that.

Okay, my two setups are here:
github.com/TriodeGirl/LinuxCNC
The AXIS one works, the Probe_Basic is the issue.
I am using a MESA 7i96s board set at 10.10.10.10
I have E-Stop enabled, and am supplying a suitable active signal to the pin input. This works under AXIS.
Many thanks.

Hi eraserhd,

Thanks for debugging this. I've not worked on the RP2040 for some time. This Remora port was a hotel room project when I was travelling for work.

I'd be interested to see a pull request to merge your work. If you have time you might also look to update the stepgen to send back the raw count like the recent Remora code for STMs, that way the latest Remora Linuxcnc component could be used.

On second thought, I will need to include the G10 offset stuff.

Just because I set HOME = 0 for both axes doesn't mean the HOME_OFFSET is the same for both.  And if I plan to use G54 offset to get the parting tool tip at spindle centerline I need the switched X-axis G54 values to be the same as V's.

Hmm...

Hallo Zusammen,

kennt jemand oder kann sich auch an das folgende Problem errinnern und kann mir helfen.

Ich habe eine CNC Spindel 2,2Kw mit Frequenzumwandler von Aliexpress. 

Jetzt habe ich ein Grundsetup vom Frequenzumrichterfür die Chinaspindel wie auf der Seite von Stephan -> Estlcam  gemacht.

Gem. Frequenzumrichter-Einstellung soll die kleinste Drehzahl bei 6000U/min sein. Gesteuert wird das Ganze über eine Mesakarte und bei der Hälfte der Drehzahlvorgabe wird auch die halbe max. Spannung also 5V von 10V von der Mesakarte an den Frequenzumrichter ausgegeben.
Soweit so gut, aber:

Jetzt verhält es sich so, dass wenn ich 12000U/min vorgebe also 5V an dem Frequenzumrichter anliegen, der aber ca 18000U/min ausgibt.

Da ja hier viele so eine China Spindel mit Frequenzumrichter haben hoffe ich ihr könnt mir helfen, wo und wie ich was verändern muss, um das die Vorgabe auch vom Frequenzumrichter richtig umgesetzt wird.

Viele Grüße
Stephan  

Lets see if I've got everything now that I've had a good think:

• INI
  • V-axis
    • change HOME/HOME_OFFSET to "0" (to match X-axis/Joint0)
  • X-axis
    • add min/max limit entries for switched state
    • add max_vel & max_accel for switched state
  • Remap M-codes
  • [KINS]
    • KINEMATICS = parting_slide (yes/no?)
• M-CODES
  • M300 - normal mode;  set #<kinstype> = 0, call M100
  • M301 - switched mode;  set #<kinstype> = 1, call M101
  • M100 - set V-axis min/max limits and vel/accel to normal
  • M101 - set V-axis min/max limits and vel/accel to switched values
• HAL
  • net KINSTYPE-SEL <= motion.analog-out-01 => motion.switchkins-type
  • (analog-out-01 verified to be free)
• COMPONENT
  • parting_slide.comp created from millturn.comp.
  • substituted @Aciera's suggested edits and added comments
  • compile/install
• OPTIONAL?
  • Add G53 G0 V0 initial move to M301 so V and X are both at "0" before switching anything
  • Some sort of safety so joint0 jogging is inhibited when switched?  Don't want to accidentally jog joint0 (actual X) when sub-spindle is clamped on to a part.
    • I will probably also add an X jog-inhibit to my spindle/sub synch sequence.
  • Some sort of safety so everything switches to normal on an abort/estop/similar

Assumptions:

1. I won't need new stepgen settings when switch is active because I'll be commanding the X-axis - which is now joint3.  And nothing about joint3 will have changed.  Millturn example M128/129 only changed the axis settings, not the joint settings.
2. I won't need the G10 home offsets adjustments in the millturn example since I will be setting V and X home to 0.

Still unclear:

• Is the INI [KINS] change, along with HAL file loadrt [KINS]... what calls up parting_slide.comp?
• what connects motion.switchkins-type to the Case0/Case1 settings in parting_slide.comp?

Comments/critique welcome as usual.

Okay, now I am understanding the pain of AI. I went in circles with compiling errors and format.

Now it compiles, but I get
hal:turret:1: character unknown '  '
and the invisible character search didn't turn up anything.

Any ideas what I have wrong in this comp appreciated...