Laser engraving module

[Pnrntn]

great job, congratulations. I hope that in the end you make everything simple even for us mere mortals, perhaps with a tutorial.

[sohejl]

Thanks for the "flowers" but to be truthfull, without mstrens I would still be juggling questionsmarks... Anyhow I will be happy to provide all necessary data and infos, when I'm finished and have it working. As far as I know romain is also working on this topic and plans to provide a tutorial. I only hadn't had the patience to wait for that. You know how it is "a laser sitting on your desk...how can you not play with it...impossible"

[mstrens]

Fine that you find a solution.

I forgot to inform you but a few days ago I made a change to the STM32 GRBL firmware.
With this change, it should now be possible to invert the PWM signal per software.
If you use this new option, you could connect directly the laser to the shield.

Romain was supposed to test this new option and I was waiting his feedback before I publish it.

You can test it if you want.
The version in on github at:
https://github.com/mstrens/grbl_6axis_on_stm32

In the config.h file you have a define with INVERT_PWM.
You can activate it.

take care: I did not test it.

[RoMaker]

Hi,
this afternoon i tested two ways :

-Directly solder the laser PWM input on the PWM pin of the STM32 (not on the board) -> it works
-Made an inverter circuit between Board PWM pin and laser PWM input -> it works

Tomorrow or thursday i will try the firmware modified by Mstrens ...

[RoMaker]

It works !
First explanations (sorry only in French for the moment) : viewtopic.php?f=47&t=6588&p=23224#p23224

[sohejl]

Great, since I was busy to build my inverter board you all brought up additional solutions, where at least some would have made my life easier

First... thanks romain for the input. I thought also on soldering directly on the ESP output, but the complete build is quite fancy I didn't want to tamper with it. So coming back to my solution to the problem... it's build - it takes all 3 pins (S/GND/5V) from the RS control board and provides the 2 pin connection (s=+ / -) for my laser PWM input.


and actually working fine and integrated und tested now in my RS-CNC with the mounted laser... as you can see it inverts the (for my laser) neccessary 5V PWM output (blue = S output of RS control board / yellow = new S output for the laser). But since mstrens updated the S/W regarding the inverted PWM out of the ESP it's nearly completly useless or at least has 3 parts too much


I think since I have build it now, I will use it (at least for the time beeing). But for everybody else who is looking for the solution I would advice to go with the simplest way possible like shown as follows => make sure that your laser works with a 5V PWM signal and keep in mind to change your grbl software with the option INVERT_PWM aktive, otherwise the Laser will emit full power with S=0 and also keep in mind what romain has written in french...
FIRST STEP - Turn on the RS-CNC
SECOND STEP - Power Up the Laser
...and vise versa for turning off, otherwise you will have the laser emit full power when you do not want it to since it has now PWM input when the RS-CNC is off.
I haven't had the time to test this new S/W version but will write again when I got the chance.

[sohejl]

Works