SKR Pico and COREXY sensorless homing

[Fiz-83]

Hello everyone,

I'm trying to set up sensorless homing for COREXY on an SKR Pico TMC2209.
I ran some tests, homing each axis individually:

• Z axis: works
• Y axis: works
• X axis: doesn’t work

I also tried changing the homing order (XYZ, ZXY, ZYX) and even tested only Z/X/Y, but the X axis never works.

Has anyone else experienced this? Could it be a bug, or am I missing something in the configuration?

[terjeio]

Can you check the voltage on X limit input (on on the P2 header which I has a link in place), does that change when Stallguard is triggered? Or remove P2 and trigger the X limit input, does that work?

[Fiz-83]

I think the problem is different now. Only one axis works at a time (sometimes X, sometimes Y).

I did some additional tests by switching to Cartesian configuration.
Here are the settings:
44 → Z
45 → X
46 → Y
With StallGuard at 60–70, it triggers without any problem.

If I switch to COREXY:
44 → Z
45 → X
46 → Y
With StallGuard at 255 (or even lower):

Z works
X works (now)
Y never works (now)

So I think the issue might be related to the COREXY kinematics.