I have an Ender 3 Pro, board version 4.2.2, and a CR Touch with 5 pin connector. I also removed the z-axis endstop connector at the endstop.
I've been building and flashing Marlin 2.1.2.2, but I haven't found a configuration that makes the CRTouch work as expected. Typically, during auto homing, the machine will ignore the probe triggering and drive Z into the bed either 100% of the time or most of the time. I didn't take detailed enough notes to know for sure.
As a test case, I tried following along with this answer exactly and still had the same problem. Configuration changes from the Marlin Ender 3 Pro default:
- Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN commented out
- USE_PROBE_FOR_Z_HOMING uncommented
- Z_MIN_PROBE_PIN uncommented and set to PB1
- BLTOUCH uncommented
- NOZZLE_TO_PROBE_OFFSET set to { -44, -9, -0.9 } (here I differ slightly from the { -44, -9, 0 } in the answer)
- AUTO_BED_LEVELING_UBL uncommented
- ENABLE_LEVELING_AFTER_G28 uncommented
- Z_SAFE_HOMING uncommented (not in the answer, but in a comment)
On my first boot after inserting the SD card with firmware:
- The probe deployed and retracted a couple of times, ending retracted with the red LED on
- The machine seemingly flashed the firmware as it sat on a blue screen for a while
- The CRTouch LED turned purple I think when flashing ended, though I can't tell from my video
- When I got to the main menu, I started auto homing
- X and Y axes worked as expected
- For the Z axis, the probe centered on the build plate, deployed, and the LED turned blue
- The probe started lowering, contacted the plate and retracted. The LED turned to blinking red, maybe steady red first. The Z motor kept driving down so I killed the power
The extruder fan also made a loud buzzing noise that gradually grew quieter. In the past I've noticed the buzzing seemingly get quieter when the probe is deployed or retracted.
Anyone know what could be causing this, or how to troubleshoot it? Creality's firmware works as expected, so it's not a hardware problem. I was thinking maybe PB1 is wrong for the Ender 3 Pro, but from what I see online I gather it's the same mainboard between both printers.