Hi Open Builds community, I am building a 3d printer from scrap and am looking to use the spindle control within GRBL to drive an a4988 (Easy Driver) controller to run a stepper motor. I have un-commented USE_SPINDLE_DIR_AS_ENABLE_PIN in config.h and have experimented with different settings for SPINDLE_MAX_RPM. I have PIN 13 going to DIR and PIN 11 to STEP on the Driver. I am able to get the motor to make a high pitched noise by sending a M3 S100 command, if I disconnect PIN 11 the motor will run for a bit and then stop. I know I am missing something here and would be very grateful for some expertise, I have Googled as much as I can. I suspect I am getting muddle between output for the spindle and the input to the easy driver but admit am a bit of a newbie to this and now a bit stuck. Thanks for reading.