My laser engraver from 0 knowledge to 32.461% .... probably

[ArtF]

Hi Bobby:

  Wont work no most lasers. The PWM is more like a way to get an analogue voltage for the controller. Most co2's
will work fine at a wide range of pwm base frequencies. In any event, time is the problem. Most lasers will not react
faster than 1-2ms in difference of power. You cant script anything to do with the grey conversions, Augie is too busy
on that stuff to change anything. You can change th PWM base frequency by script..  but generally your better
off with whatever the spec is..

  TO play with effects, Id more recommend going with multiple pass techniques for things like dithering patterns..

Art

[BobbyW]

Hi Bobby:

  Wont work no most lasers. The PWM is more like a way to get an analogue voltage for the controller. Most co2's
will work fine at a wide range of pwm base frequencies. In any event, time is the problem. Most lasers will not react
faster than 1-2ms in difference of power.
Art

Hi Art
I resume all facts until now and i suppose i jump in a error  without thinking is a error.
So , let me explain.
First off all if you remember i has a hard time with my very low impedance source and residual voltage input at 1.2v or something.
Well i fix that and starting to develop different interfaces i end from high end PWM to DAc converters to banaly MCP or LM324 OP.
Work good so fare but when i develop all that stuf i do it blind in FR without even have a banal osciloscope. Back home i have everything i need.
So i start measuring everything and i found the issue.
Here we talk of 3 different solutions to control the analog laser input.
1: My solution was to made the PWM between 0-800mv and find the laser trigger point by linear contrast in auggie.
Not bad but the resolution is limited by any type of photo in different ways.I put below a paper to explain my old solution.

2: Is you solution. To reformat the signal with atmega help . Well not bad at all but after i made my own to testing i run in one
issue when i look closely with magnifier what happen on polywood. So i found a saw mark on the end of black parts and whyte parts
(at least that was very visible). So thinking why , i change my microcontroler to one with PLL and FRC up to 120MHz.
Was totaly wrong , that marks still exist and after some time i realize , doesn't matter how fast my processor is
he will always wait to measure the input signal to be able to give the out 50% signal or any division.
Is true it is some improvements , but when X go from 0 to 100 (as example) the delay will be in left side
and when the X will return the error will be in right side , at the end the little error will be *2.
I try it , and also i try to made a linear OP divider . The result is way better but not as i expect.
I put below a printsc from that.

3: That is last one and i think is the best solution to have on any type of laser a full resolution between
black and white and also simple to be adjustable.
What i think is (as example ref). If the laser start to leave a mark on polywood from 300mv input and up to 700mv on max black
basicaly we need to have a 400mv PWM with +300mv offset . In that way the laser will be prepared to start burning
and the PWM will be in full black white resolution.
I put a printscr below on what i thing is the best way. Now i try to find a good OP with good adjustable offset
So fare i found the https://www.analog.com/media/en/technical-documentation/data-sheets/AD8220.pdf
but i still search.
I hope will help and my english ahh is hard

Thanks
Bobby

[BobbyW]

Hi.
Well can not sleep until to finish my idea .
I made fast with one Op LM358 was close to me.
I have some single supply rail to rail OP but can't find when i need it.
The PWM don't reach more than 2.45V but to engrave i need no more
than 700mv.
That is the vid with my old technique with linear contrast in AUGS.
https://youtu.be/k26aoKRzsGE
And this one with what i think is better result and at least standard for most
of wood materials.
https://youtu.be/vpEETVXhbrQ
The wave is not perfect , can see some ripple but i will move one to
AD8220 have built in reference offset.
That's for now , more test commin'
The first photo engraved like that , and very small size. Before was impossible to go
below 140mm W
Thanks
Bobby

[ArtF]

Bobby:

  Your English is far better than my version of your native tongue.

I think I see what your speaking of. Your laser seems unusual in that its very
tight on control. All of mine are really end controlled by average voltage, but
its not close to your sensitivity. Your schematics seem to show a very close
tolerance to the voltage swing of the pwm. Synrads dont tend to be that
sensitive. They have a max of 20Khx and simply average the voltage
from a 1ms pwm to a range of perhaps 500 steps internally. It looks
from your circuitry that the power range you seek is very tight..and probably
specific to that laser.
  I congratulate you though on your solution and experience, you really
tracked it well, I think you have tighter control than most.

  I like your solution, the ability to test the actual range output was clever...

Good work.

Art

[BobbyW]

Bobby:

Your English is far better than my version of your native tongue.

I think you have tighter control than most.

Art

Hi Art.
Thanks for the kind words . Usual people correct me in not a nice way , but
i say to all " if they realy want , can correct me in my native language"
I'm Romanian , i speak very good Ru and Fr language , in my time english wasn't on
school . I run in it in my faculty , of course technical english , but still .
About my laser control , well i think is the source issue. Is very tight on small power
rise fast , and after decrease until 4.2V = 20mA. I dont use more than 10mA but
the control look like 30% logarithmic increase and after keep some linear shape.
Hard to tell without measure device on laser power.
I finish my interface , i solve that little noise on voltage offset (i was stupid , no any decoupling cap
and no small low pass to first AO input. I was tired. Is solved all .
Now i run in my OLD issue . I don't get what's going on , i just dont understand .
I made a small switch between normal power for cutting and power with offset for engrave .
I change all stats with one single signal from OC 1 of Pokeys.
Well i write the code for button switch , i create the button , the variable are in system and are called
when i press the button but NO way to get the output ON on any OC.

Code: Select all

 
Variable GravareButton calls with current:1.0000 
 thread 33 started.
 thread 33 stopped.
 Variable GravareButton calls with current:0.0000 
 thread 34 started.
 thread 34 stopped.
 Variable AirButton calls with current:1.0000 
 thread 35 started.
 thread 35 stopped.
 Variable AirButton calls with current:0.0000 
 thread 36 started.
 thread 36 stopped.

I mean working in midi script , also first time i create that function , was perfectly normal.
Work without issue .
I turn off the laser and Auggie and i go to sleep . After i wake up , i say to edit the name of button
was "EMPTY" and to change the color. I do it without start the laser. After i save the screen and i start laser
nothing work anymore.

Code: Select all

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//Toggle the output of the button for engrave
global	GravareButton = function()
{
  if (Gravare.GetState() == 1)
  {
    Pokeys1.SetOC(1, 1);//set putere gravare
    yield();
  }
  else
  {
    Pokeys1.SetOC(1, 0);//set putere taiere
    yield();
  }
return;
};
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

And declared here " don't know if the order matter " some compiler do.

Code: Select all

global Gravare=Button("Engrave_BUT_66");

And check below in while loop.

Code: Select all

global	TheWatch = function()
{
while(1)
  { 
    LedButton();
    AirButton(); 
    GravareButton();   
    Safety();
    yield();
  }
return;
};

And the button is pic below.
I dont get it why doing that . If i turn on the OC1 in midi script and i press
button the OC 1 will turn off. Maybe that help.For me is mistery.
I remember , i run is same problem when i try to made the button for compressor .
Finaly got it working and after never stop.
Also what is mean " ID number " Any button created start with -1 .
Thanks for now.
Bobby

[BobbyW]

Hi
Well i think i found the issue.
I dont know if that's true but now working.
Becoming tired , i didn't pay to much attention and i become frustrated
in one point . Simple things made you crazy .I assume exist some order to
create that. I saw later after i delete everything and start over , soon you create
a button , will be assigned a variable for that. And that corespond to the ID of button.
My mistake, i was think i need to create my "own" variable , otherwise
the function don't make sense.

Code: Select all

global Gravare=Button("Engrave_BUT_66");

I modify that after i create , to be easy to find after.
I delete again , to start over  .
Now the big question . " how i can delete a variable from system "
even i comment the function , that remain in system.
I just comment right now , but seems that wont dissapear
after. And was some restarts , even on OP system. I put pic below.

Thanks
Bobby

[ArtF]

Hi Bobby:

So you need to remove the function.. commenting it out wont work,
the parser doesnt see comments, it is just looking for function names.
Try breaking up the name while its in comments. Such as

//  function MyButtonControl()...

becomes
// func tion MyButtonControl(//)

That should do it.

Your problem is  typical, as you learn you try to overthink it.. but buttons and variables
are very simple in reality, add one and they tend to work automatically by their name.

  Good go though, you really seem to have figured it out, no small feat with Auggie..


Art

[BobbyW]

  Good go though, you really seem to have figured it out, no small feat with Auggie..


Art

Hi Art
Yea , true it is simple " when you know" if you don't , not realy.
And you right , most of best solution are the simple one , people tend to
overthinking.
I finish the interface , work as expected , now become some test's.
Didn't see much difference in the results but for one thing i'm sure,
the control is way large and easy to find the sweet spot for material.
I post the schematic , is simple easy and working with no delay
as analog do. The interface was made on the knees " just for test"
but is working . And to be honest i dont think i will bother to made
the circuit board in the future.
I give up with NPN open collector transistor for function switch ,
seems inducing some bad ripple in the system.
I end with a very cheap MUX and is way better and remain more channels to "update".


Thanks
Bobby

[BobbyW]

Hi everyone .
Time by time , getting experience . Never work before with
stuff like that .
Seems not only engraving give u a satisfaction.
It is a monastery from my town . Was made it long time ago
and my wife give me a chalenge .
I hope u like it
https://en.wikipedia.org/wiki/Curtea_de_Argeș_Cathedral

Thanks
Bobby

[ArtF]

wow, awesome. Thats  a LOT of work ...

Art