Laser Intensity

nlancaster

Hello all,

Trying to add laser engraving to my 3d printer.
I have been able to get the laser to turn on and off with M3 S255 and M3 <S255.
But I would dearly love to enable intesnity settings.
My laser has a PWM input that is being triggered by Pin4 as configured in my firmware, but I am missing some setting or configuration that allows PWM to work.

Here are what I believe to be the relavent files. Thanks!

configuration.h - https://pastebin.com/LDhZ5i0U events.h - https://pastebin.com/wUTPFEBx drivers.cpp - https://pastebin.com/P9RMTYcs

Repetier

Please check the forum. There is at least one thread in the recent past describing how to do it. In the github sources you will even find the matching modifications from RayWBa in the sample events directory.

nlancaster

if by chance you mean this thread:
http://forum.repetier.com/discussion/1387/implementing-laser-intensity I have been looking at that thread off and on for the last 6 hours. information is talked about hte implementation in both the firmware itself comments and that thread but much information is just plain left out.

Repetier

No more like this one
http://forum.repetier.com/discussion/comment/17741/#Comment_17741

nlancaster

Looked into the github.

Tried to implement what I found here, but now I get now laser on m3 commands.

https://github.com/repetier/Repetier-Firmware/pull/524

Repetier

Laser turns on when E value exceeds or with M3 Sxx. But it only turns on for G1 moves. When not moving or for G0 moves the laser stays off. That way you can use G0 for positioning and G1 for engraving.

nlancaster

Sure I understand that, but I am getting no laser while moving on G1 or G0 with M3 S0 to S255.

Repetier

Have you already tried without the pwm modification? PWM only works for very few pins that are bound to a timer that does not get used by firmware.

nlancaster

Yep, laser mode works fine without PWM. wiht just the built in laser mode in 0.92 firmware.

ChicoCybergoth

Hey bro, found a final solution for this?
I just need a simple PWM output pin to drive my laser.
I'm using Arduino Mega with RAMPS 1.4

Mikelangelo

You can take fan2 output (print cooling fan).Its PWM and can be controled easy.

Repetier

No, it will not sync and PWM is very slow, not fast enough for a laser. Better use
https://forum.repetier.com/discussion/6363/laser-enable-pin-issue#latest

Mikelangelo

Is it possible to make simple SG3525 PWM (I am asking logicaly - making pwn is out of the question)......that works on 100KHz to 400KHz and simply tune manualy lasser output power?It can easy go from 1% to 99%.

Repetier

That might be a good solution also I have no idea how to set PWM for that chip. You just would need to add the custom event for laser to set value to that chip and it would work. Surely faster then what the avr will create.

ChicoCybergoth

Repetier said:

No, it will not sync and PWM is very slow, not fast enough for a laser. Better use
https://forum.repetier.com/discussion/6363/laser-enable-pin-issue#latest

Repetier solution is 100% and VERY easy to implement!
I recommend!
Just 1 line to change.
I chose pin 44 (Aux 2 - RAMPS 1.4)

Mikelangelo

PWM for sg3525 can be set with potentiometer on the board or with voltage (analog) control.I will post schematic here today.

Repetier

But we have no analog voltage. All we have is a pwm output. So you use a pwm signal to create a pwm signal. Guess if there is a capacitor somehow involved to stabalize voltage it should work.

Mikelangelo

I can make it to work that way easy.This is my area.No prob.Whats pwm frequency available from arduino?

Mikelangelo

Let me know whats fan2 output pwm frequency too.Lets make something easy to implement.

ChicoCybergoth

Repetier can answer better, but, AFAIK the fan output has a very slow PWM frequency.
But, if you said that PWM controller can be adjust by a potentiometer, this can be interesting also, the machine enables this external PWM but its duty is adjusted manually by potentiometer, if it has an enable pin is just hook to the LASER_PIN.