Hi, the definition of the coolant pins as #define COOLANT_FLOOD_PIN GPIO_NUM_34 #define COOLANT_MIST_PIN GPIO_NUM_36 are useless for the ESPduino32 because these pins are "input only" pins. This should be mentioned in the header at the same place as the "R1 speciality". In my application I mapped the COOLANT_FLOOD_PIN to GPIO04 (and the unused COOLANT_MIST_PIN to GPIO32), because I don't use the "Feed Hold" input... Regards, Thorsten