I am adding a laser to my MPCNC with Arduino Mega 2560 with Ramps 1.4. To do this I am attempting to remap D9 fan to pin 44 (pin 7 of Aux2) for PWM control of the laser. I was running Marlin 1.0.1 and read that this had bugs in it. I have since updated to Marlin 1.1.8 which is supposed to be the latest and greatest. It is compiling and loading OK but my D9 is still active and pin 44 seems to be sitting around 2 VDC all the time regardless of what I have the fan set to.
Any tips on how to fix this? Is there a better pin for me to map to?