SKR PRO Laser Issues Again

Hey All,

I had an issue a while back on the PC9 pin going bad on my SKR board so I swapped the pins in the config.h file to PF9. This time around I cannot get the laser to turn on when running a cut with lightburn (the pin was previously working), I have the Inline option selected and have tried different baud rates, I double checked the wiring and tried a different laser board.

I recompiled the config.h again to PC1 and when I start a cut in lightburn the laser will “flicker” but not stay on, power is 100%.

Any ideas or see something I am missing?

Thank you, Brady

You appear to have two entries for -

I dunno if that is what is causing your problem but I would suggest you either comment one set out or just delete one set leaving just


Thank you, I commented a set out and recompiled. When I go to start the laser cut now in lightburn it doesn’t “flicker” or power on at all

I think I would start looking at the signal levels on PC1, ideally with a scope (the basic ones are so cheap now, under $25, I really can’t see a reason not to buy one), otherwise a meter is a poor second choice. If the signal is there check it at the laser, if it isn’t there check for the enable signal on PB0 and suspect your SKR.
I assume the settings in Lightburn are ok if you had it running before and haven’t changed any settings but I don’t use Lightburn so couldn’t advise you further on that.

Cheap scope

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