Cannot seem to get PWM control.

Lasers
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1

Cannot seem to get PWM control. 2.4 (White) and 3.3 (red) are VCCA, Laser on LPS (White) and 5v (Yellow). I always get 100%.

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2

Need to know some more information to help.
Controller, wiring etc,
This form may help you organize the information:

This is a place to start.Look for sections on PWM control and smoothie wiring. Don's Laser Cutter Things: Click Here for the Index To K40 Conversion

3

Im using a smoothie 3x. Ive read through your guides.

4

Thanks for using the form.
I need to better understand exactly how you connected your PWM. It looks like in the picture you are using a level shifter? A level shifter is not needed.
Did you review this: http://donsthings.blogspot.com/2016/11/k40-laser-power-supply-control-take-2.html

5

the picture that is worth 1000 words :slight_smile: credit to @donkjr as my original source.

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@Domm434 working?

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oh im not the orginal poster, just another helping hand and giving you your due credit

8

@Domm434 whoops, need my coffee :).

9

@donkjr The laser wouldn’t fire until @Scott_Marshall helped me set up the leveller.
@Domm434 That schematic is for the 5x. I’m using a 3x. My PS looks different as well.

10

Let me make sure I understand. I have a GGGG. I disconnect the leveller. I don’t use 2.4 or 3.3 and simply connect PWM0 to L?

11

@Jerry_Hartmann

…

I assume:

  1. that “2.4” refers to the PWM pin that is on the header on the board?
  2. “3.3” refers to the 3.3V on the header that feeds the level shifter.

…

Its unclear to me if this was ever working, not filed in on your problem profile?

  1. Was this working? If yes what did you change that may have caused this problem?
    …
    We have a choice:

4.a. to try an fix what you have i.e. level shifter config.
4.b. rewire to use the “L” input.

@Arthur_Wolf I searched and could not find the schematic for a 3X, did find the 5X.

12

I belie i put in the profile that it always fires at 100%.

I can tru removing the shifter but i need to know which pin to solder for ground as thr 3x lacks all the connectors the 5x has

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@Jerry_Hartmann as a help can you answer the other questions above?

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  1. Yes 2. Yes 3. See above 4. Either
15

@Jerry_Hartmann ok it was working and now it isn’t, what changed?

16

I never had pwm. I could fire the laser after the leveller was installed but i can control the power output with software

17

@Jerry_Hartmann did you mean " i can cannot control the power output with software".
I am having trouble finding info on the smoothie 3X can you post a picture with all connectors showing?

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the smoothie 3x and 5x are identical boards minus the extra smt drivers and required components. board layout and pin location remains the same @donkjr for reference. i know if you get a 3x vs 4x it doesnt have all the screw terminals or the lan jack included.(4x and 5x its standard)

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@Domm434 @Jerry_Hartmann thanks I just found that out :). That’s why there isn’t a separate schematic … I will take a look and come back with recommendations.

20

@Jerry_Hartmann this should be straightforward. The blog post sited above applies to your 3x board.

The P2.4 (PWM) connector is populated just like the 5X picture (white wire).
The connector that is used for ground (black wire) in that scheme is not populated in the 5x but you can pick up the ground right off of X13 on board where the connector would have been installed.

The attached layout graphic shows more detail.

Verify your ground with a DVM to be sure you have the right pad.

If you wire it up as this suggests and post a picture before trying I will check it for you.

Note: you have to change the configuration file to match this setup (P2.4).

See that in the blog post.

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