BL Touch Install ... need help

(Darryl W. hughey) #1

I have recently installed a BL touch onto my printer that did not previously have auto bed leveling features. I have modified the firmware. The pin extends and retracts with commands M280 P0 S10 to extend the pin and M280 P0 S90 to retract it. I have the signal correct as it shows triggered when it is retracted. However, the pins remains retracted at all times when trying to home and always thinks it is triggered and keeps rising. Am I missing something in the firmware that will tell the pin to extend while homing?

Thanks for any help

(ThantiK) #2

You may need to invert what the firmware defines as ‘pressed’. Which firmware are you using?

(Matthias Burkhardt) #3

Did the same recently and it worked out well:


Do you use Marlin FW and a RAMPS board?
There is a special section in the Marlin FW for BL Touch, maybe you missed something to decomment here?