I've been working on a delta based CO2 laser cutter. I need help finding the PWM pin that normally controls the printhead fan speed (D9). I would like to use this to control my laser's power by issuing M106 SXXX to my RAMPS 1.4 board.
So far, I have been able to upload the basic "Fade" arduino sketch to my stand alone arduino. Once I connect the laser to the appropriate PWM pin, it responds just like an LED would (fading in and out). This tells me my other circuitry is good. All I have to do now is find the right pin the arduino and connect to that, correct?
What pin does marlin + ramps use to control D9?
