I recently got a Smoothieboard clone in the hopes of making a water jet cutter. I planned on using the laser functionality of smoothieware and simply changing the cutting element. However I did not realize that the laser uses a PWM signal to raise and lower the laser power rather than just turning on and off. In the G-CODE the laser power is set using the S parameter from 0 to 1 and is sent to the PWM pin. However I need the signal to activate a relay. The switch function alone will not pick up on the S parameter as it is technically not a command. Is there and easy way to make it look for S or should I try something else? I was thinking that I could set an input pin and jump from the actual PWM for the laser to a new input pin for the switch. Then I could make the switch watch for a high signal coming in and turn on the relay. In my experiences however I am not sure if I have everything set up correctly. I am using a MKS SBASE V1.3 from amazon and I am using this configuration for the laser function.



I also have some G-code to test the program.
This code only cuts out a small circle

After some tinkering it seems that the board does not respond to any laser commands I give it. The G1,2,3 and fire commands do not send a pwm signal and the ttl pin does not activate. Is this unusual or should I just buy a real Smoothieboard?

SOLVED

Since I was using Fusion 360 to generate G-code I found out that I could change the laser power in the post processor. Instead of generating G1S1 I can change it to create G1S255. From there A switch set to read PWM will be able to activate my SSR when the "laser" begins to cut.
That being said I am still not sure why the laser module wasn't working properly.