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Forum Index : Microcontroller and PC projects : G-Code interpreter in BASIC anyone?

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Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 01:24pm 10 Oct 2022
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Shouldn't take much to do this but just wondering if proven code already exists.

Looking at making my motion controller compatible with

GrblGru

MMBasic should be perfect for this  


Craig
 
Martin H.

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Joined: 04/06/2022
Location: Germany
Posts: 1233
Posted: 01:33pm 10 Oct 2022
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You wish, the Pico to controll the Steppermotors of your CNC?
Something like "Marlin"?
But I dont know if there is a Marlin Version on the Pico.
Couse most 3D Printers / CNC use Arduino Board to do the Job.
'no comment
 
circuit
Senior Member

Joined: 10/01/2016
Location: United Kingdom
Posts: 277
Posted: 01:51pm 10 Oct 2022
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  Tinine said  Shouldn't take much to do this but just wondering if proven code already exists.

Looking at making my motion controller compatible with

GrblGru

MMBasic should be perfect for this  


Craig


Gosh, you have really got my interest.  I am just starting out with the idea of building a CNC router and this sounds like a possible way to go.
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 02:15pm 10 Oct 2022
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  Martin H. said  You wish, the Pico to controll the Steppermotors of your CNC?
Something like "Marlin"?
But I dont know if there is a Marlin Version on the Pico.
Couse most 3D Printers / CNC use Arduino Board to do the Job.


No, the PicoMite is the front-end to my Parallax P2-based motion controller.

The objective is to provide a proper closed-loop-servo alternative to all of these stepper systems    

CNC = Computer Numerically Controlled

I regard open-loop steppers: Computer Numerically Commanded

No feedback = no "control".

In fact, my method is to utilize "dual-loop-feedback". The device highlighted in red is what is typical and provides loop stability but the controller is never aware of mechanical backlash. Maintenance personnel can't understand why parts are varying when the controller always reports "axis is within tolerance"  

I prefer to use both the red and yellow highlighted devices to provide stability and backlash immunity (within reason).





Craig
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10310
Posted: 02:57pm 10 Oct 2022
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  Quote  The objective is to provide a proper closed-loop-servo alternative to all of these stepper systems


Have you looked at closed loop steppers? - cheaper than servo technology but with the same guaranteed accuracy with the right driver
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 03:35pm 10 Oct 2022
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  matherp said  
  Quote  The objective is to provide a proper closed-loop-servo alternative to all of these stepper systems


Have you looked at closed loop steppers? - cheaper than servo technology but with the same guaranteed accuracy with the right driver



Yeah, still too limited.

Torque drops-off at a half-decent speed and they can't get close to the 3,000 - 6,000 RPM that I use.

The biggie for me though is that they can't be torque limited and this is the problem I have with Annin Robotics.

He's doing an amazing job and finally switched to closed loop but closed-loop steppers.

Today, robots are becoming "cobots" (collaborative robots). They can work alongside humans without a protective cage because they are able to torque-limit.
A setup person used to have to use a teach pendant whereas now they can simply grab ahold of the end effector and drag it around and have the cobot learn the path.

This is all achieved by limiting the output of the PID filter.

I have used this method for decades for setting-up my machines. If it crashes, all we get is a harmless "thud".

Examples at 1:43 and 4:13

Craig
 
led-bloon

Senior Member

Joined: 21/12/2014
Location: Australia
Posts: 207
Posted: 03:17am 11 Oct 2022
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I doubt this will be any good for you, can't find
any of my doco/drawings with it, and (unusually) very
few comments in the code.
Good for a laugh or how not to code it, maybe?
led

mite-cnc.zip
Miss you George
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 04:55am 11 Oct 2022
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  led-bloon said  I doubt this will be any good for you, can't find
any of my doco/drawings with it, and (unusually) very
few comments in the code.
Good for a laugh or how not to code it, maybe?
led

mite-cnc.zip


There we go      

Many thanks  

Craig
 
Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 5089
Posted: 05:19am 11 Oct 2022
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  Tinine said  .


Today, robots are becoming "cobots" (collaborative robots). They can work alongside humans without a protective cage because they are able to torque-limit.
A setup person used to have to use a teach pendant whereas now they can simply grab ahold of the end effector and drag it around and have the cobot learn the path.

Craig


I have a colleague workin on one. They run on several NVidia Jetson modules, accompanied by a RPi4 for motor control. The NVidias are used for AI and protecting the humans.
PicomiteVGA PETSCII ROBOTS
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 06:18am 11 Oct 2022
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  Volhout said  

I have a colleague workin on one. They run on several NVidia Jetson modules, accompanied by a RPi4 for motor control. The NVidias are used for AI and protecting the humans.


Cool. Is this a new development?
 
Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 5089
Posted: 06:25am 11 Oct 2022
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watch this:

video
PicomiteVGA PETSCII ROBOTS
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 06:49am 11 Oct 2022
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  Volhout said  watch this:

video


But running on an RPi4? Must be bare metal if it is   They still have latency/jitter issues when running 3-axis LinuxCNC.


Craig
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 07:25pm 11 Oct 2022
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Linux CNC RS274.pdf





Craig
 
Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 11:14am 12 Oct 2022
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Have been in touch with the creator of GrblGru. I really hope he's up for it.

I have a mill here that needs a new CNC and I'm totally underwhelmed with every existing option out there. All half-baked IMO  



Craig
 
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