🔧 Sanity check BIQU MicroProbe and FT_MOTION

[narno2202]

Description

Currently Z homing is impossible with a BIQU MicroProbe when FT_MOTION is enabled. You have to disable FT_MOTION with M493 S0 in order to home the Z axis.

After some investigations, homing is fine when ENDSTOP_INTERRUPTS_FEATURE is enabled on a compatible motherboard.

Add a comment in Configutation.h in "BIQU MicroProbe" section and a test in SanityCheck.h when FT_MOTION is enabled with this probe.

Requirements

Motherboard with interrupt capable endstop pins.

Benefits

MicroProbe works as expected

Configurations

Related Issues

None

[thisiskeithb]

Interesting. That's going to preclude most (all?) LPC-based boards if they have a MicroProbe and want to use FT_MOTION.

[thisiskeithb]

You have to disable FT_MOTION with M493 S0 in order to home the Z axis.

What about disabling FT_MOTION (and INPUT_SHAPING_Z) automatically as standard procedure for all Z homing with a probe? This would remove the ENDSTOP_INTERRUPTS_FEATURE requirement & allow a MicroProbe and FT_MOTION to work on every board.

[narno2202]

In my mind, the best is to get FT_MOTION to work with all kinds of probes without disabling anything. But it could be a workaround if no solution is found with board without interrupt feature (I write a code but I need to test it).

[thisiskeithb]

In my mind, the best is to get FT_MOTION to work with all kinds of probes without disabling anything.

There's no reason why you need Input Shaping or FT Motion during homing moves, so it's perfectly reasonable to temporarily disable them in order to home/calibrate the machine.

[narno2202]

Regarding FT_MOTION, it's simply a motion system with optional input shaping. If it's intended to become the default motion system, everything should work without workaround.

[thinkyhead]

Be sure to CC: to @ulendoalex for all issues related to FT Motion since Ulendo has a vested interested for everything to work seamlessly with this new motion system. Breakage of homing or probing with FT Motion enabled indicates a bug still exists somewhere in the design.

[narno2202]

@thinkyhead , @ulendoalex , @thisiskeithb , currently on my printer (MKS Monster 8 V1 and TMC2226), Z axis homing with FT_MOTION enabled works out of the box with mechanical endstop, BLTouch, CRTouch or SMARTTouch.
For a Biqu Microprobe V2, I need to remove the diag pin jumpers for the Z axis for a correct Z homing when FT_MOTION is disabled. With FT_MOTION enabled for now, ENDSTOP_INTERRUPTS_FEATURE is mandatory, to correctly home the Z axis.
It will be of interest to have feedback with other probes as the failure is perhaps related to the hardware conception of the Biqu Microprobe.

[thisiskeithb]

I need to remove the diag pin jumpers for the Z axis for a correct Z homing when FT_MOTION is disabled.

DIAG jumpers should be removed for any axis that you are not using sensorless homing/probing on (included all E-related axis), so that's not a new requirement.

[narno2202]

I know that, but I forgot to remove them when I change my motherboard but everything was working fine with the jumpers in place (even Z axis homing).
I made other tests, but everything fail. For now the best solution is to enable ENDSTOP_INTERRUPTS_FEATURE.