Probe already triggered...

TomW

Yes, the ghost is back inside my Duet 3 mini-5+, with RPi-5 nvme, and RatRig Vcore3 400, BL Touch probe. Firmware on both mini-5+ and toolboard are v3.5.3.
I've watched it do it, watched it carefully. Running a G29 bed mesh, I can see it:

move to new position.
Probe twice
hesitate (shudder?)
Lights inside the Probe blink
DWC declares "Error: M280: Probe already triggered before probing move started"

Okay, wtf just happened? Something balked at movement or the motion shuddered or stumbled?

I've torn down the hotend and re-torqued screws, no damaged parts. New belts and all pulleys have been recently replaced. Frame nuts re-torqued..

Why did the probe behave that way, or did it? Is this a software / trigger edge / debounce signal problem? Or did the probe somehow fault (blink) while indicating a failure. Or did the RepRap software tell the probe to blink like crazy?

Who's on Second?

What happened?

droftarts

@TomW I'd guess either the BLTouch is failing (particularly if you use it in a heated chamber), or there's a cabling issue, i.e. loose/damaged wire, which is causing the probe to reset. It might also be interference on the PWM/control wire causing the probe to reset, rather than deploy.

Basically, check the cable for good connections, consider replacing it if it's a cable that flexes as the toolhead moves (may be broken wires internally due to fatigue).

I don't think this is a firmware issue, but may be worth updating to 3.5.4 for bug fixes: https://github.com/Duet3D/RepRapFirmware/releases/tag/3.5.4

Ian

TomW

@droftarts
Hmm, yeah, I've been putting this off. I was deep into another project when I got the duet toolboard installed. Haha, the wiring is a bit "edgy", time to redo it.

If you know anything about the firmware interactions between the toolboard and the duet mini; How does the tool board signal back that the sensor (probe) has been seen? Is that a CAN packet / exchange?

dc42

@TomW said in Probe already triggered...:

How does the tool board signal back that the sensor (probe) has been seen? Is that a CAN packet / exchange?

Yes, when the state of the BLTouch sense output changes, the tool board sends a CAN packet to the main board.