I have 2 printers, an Artillery Sidewinder X1 and an Ender 3 that both have BLTouch sensors installed. This post is about the one (BLTouch clone, the probe is a Smart v3.1 sensor) installed on my Ender.
I recently upgraded from Creality's original motherboard to the BigTreeTech SKR mini E3 and touchscreen. Once I had plugged everything in, I flashed the latest firmware with edits made only to suit my BLTouch. I am using the
Zmin endstop pin rather than the dedicated BLTouch pin and I double-checked both my wiring and my firmware to make sure my changes were correct. I powered on the printer and everything worked. I even printed a test calibration cube. I was happy with myself for getting everything to work first go and screwed the lid back over the motherboard.
Upon restarting the printer, I tried homing it and the probe would not deploy, and if I did not switch the power off, the extruder assembly would drill into the bed. Using the 'Deploy', 'Stow', and 'Test' buttons do nothing. Running
G29 or tapping the ABL button on the touchscreen will return similar results to pressing home or running
G28, where the probe will not deploy (or stow if I manually pull it down - note that it does not go into error mode when I do that) and crash into the bed.
Things I have tried already:
M420 S1- returns
failed to enable bed leveling, invalid mesh
M502after it to clear EEPROM
Double checking that the servo pin is connected to the right socket on the motherboard
Swapping the BLTouch out for the one that belongs to my other printer
Using a multimeter to check the connection between the BLTouch and the servo pin
Flipping the servo connector
Using the whole BLTouch connector instead of plugging the Z wires of the BLTouch into the Z endstop port and changing the firmware accordingly.
I used this diagram to wire the sensor:
So I am just about at my wit's end with these BLTouch (clone) sensors - with 3 separate posts on this forum regarding them, my own posts even showing in the 'Similar questions' box at the time of writing this post, but amongst all the frustration I have experienced, I have learned a great deal along the way, from the core workings of the firmware to the design of the motherboard.
4 months later and I still never solved the problem. It seems likely that is a wiring fault or something wrong with the firmware but I have checked the wiring countless times with a multimeter, testing the BLTouch with another printer and using pre-compiled firmware sent to me by BTT support. I am writing to BTT to see if I can get a replacement board but if you have any other ideas I would love to try them.