FT_MOTION: Disable FT-MOTION for homing and probing for Biqu Microprobe

[narno2202]

Description

As the 2 workaround found, are far away from universal. Disable FT_MOTION for homing and probing when a Biqu Microprobe V1 or V2 is present.

Requirements

Benefits

Allow more printers to use FTM and Biqu Microprobe

Configurations

Related Issues

Need feedback and test

[thisiskeithb]

We should be fixing the actual issue instead of adding more sanity checks/workarounds.

[narno2202]

@thisiskeithb ,
I totally agree, but for now I just found those two workarounds to use Biqu Micorprobre with FTM. Do you have the possibility to test this probe? I found strange to solve the failure by lowering the Z motor current : hardware related?.

[thisiskeithb]

After some testing with a BIQU Hurakan (Manta M4P, TMC2209s, MicroProbe V2) using 3d7ac16, here's what I found:

Enabling or disabling ENDSTOP_INTERRUPTS_FEATURE with FT_MOTION enabled still causes immediate probe trigger as Z homing starts & causes homing to fail.

Halving Z homing current from 800mA down to 400mA (even testing down to below 300mA), with or without ENDSTOP_INTERRUPTS_FEATUREstill causes immediate probe trigger as Z homing starts & causes homing to fail with FT_MOTION enabled.

There are no homing or probing failures (with or without ENDSTOP_INTERRUPTS_FEATURE) with FT_MOTION disabled or not compiled in.

This sanity check is not a fix and should be removed / moved to FT Motion's docs as a possible troubleshooting step and not a strict requirement:

Marlin/Marlin/src/inc/SanityCheck.h

Lines 1398 to 1400 in 3d7ac16

	#if ENABLED(FT_MOTION) && DISABLED(ENDSTOP_INTERRUPTS_FEATURE)
	#error "BIQU Microprobe requires ENDSTOP_INTERRUPTS_FEATURE with FT_MOTION."
	#endif

Same goes for the changes introduced in this PR. Neither work for my hardware.

More testing needs to be done on wider hardware so we don't end up with overbearing sanity checks or better yet, do as I suggested in #27302 (comment) and temporarily disable FT_MOTION during homing/probing.

[thinkyhead]

There are ways we can track down the cause. We can add code to look at the direction bits and at the places where we expect the logic flow to go when things are working correctly, then look to see what's not happening, and from that it should be pretty clear why.

[EdenNelson]

Unfortunately, this workaround isn’t effective for BIQU Microprobe V2 with BTT Octopus Pro v1.1 H7. Z Endstop port or BLTouch Port.
G28 on probing fails when reaching power-on Z0.
While troubleshooting, I found that M119 shows Z_probe triggered at power-on if the probe is connected. I tested with two V2 probes with the same results.

SENDING:M119
Reporting endstop status
x_min: open
y_min: open
z_probe: TRIGGERED

This seems to be related to the Z_MIN_ENDSTOP_HIT_STATE LOW / Z_MIN_PROBE_ENDSTOP_HIT_STATE LOW.
If the probe is not connected, the z_probe is not triggered at power-on G28. Probing will move below power-on Z0, but obviously, it will crash if allowed.

[narno2202]

I assume that the probe is working fine without FT_MOTION enabled. The M119 gcode gives the same result on my printer with a working Biqu Microprobe V2. Homing is fine with FT_MOTION enbaled with this PR.

[EdenNelson]

I assume that the probe is working fine without FT_MOTION enabled. The M119 gcode gives the same result on my printer with a working Biqu Microprobe V2. Homing is fine with FT_MOTION enbaled with this PR.

No unfortunately, it's the same result with or without FT_MOTION.

[narno2202]

If you have compiled Marlin with FT_MOTION commented in Configuration_adv.h and probing fails, it's related to the hardware : wrong wiring, bad configuration or hardware incompatibility.