[SOLVED] BLTouch on Duet 2 Maestro not responding

  • I've quadruple checked the wiring and the configuration.

    The probe goes through it's test on powerup, deploys and retracts twice just fine.
    M280 P64 Sxxx commands do nothing.
    deployprobe.g and retractprobe.g are there if needed.
    M401 does nothing.
    I did follow the recommendation in the troubleshooting to cut the trace on the probe and plug into 3.3v. This is a genuine BLTouch V2.

    Here is my config for the probe.
    M574 Z1 S2 ; Set endstops controlled by probe
    M558 P9 X0 Y0 Z1 H5 F500 T5000 ; Set Z probe type to bltouch and the dive height + speeds
    G31 X35 Y110 Z0 P25 ; Set Z probe trigger value, offset and trigger height

    Any ideas?

  • I had nothing but trouble with the bltouch like this. I cut the thing to for 3.3V - but none the less, I have it plugged into the 5V without any problems made manifest.

    On 3.3V what it seemed to do mostly was just error out most times. It was as if it didn't have enough power to even raise the pin.

    Of course this is not an endorsement to plug in 5V in the part you have made for 3.3V, your kilometreage may vary.

  • Have you seen this? https://duet3d.dozuki.com/Wiki/BLTouch_Troubleshooting

    What firmware version are you using?

    Can you post the contents of deployprobe.g and retractprobe.g?

    Does the pin do a self test at power on?

    You can remove the X0 Y0 Z1 from M558, they are no longer needed.

  • The troubleshooting was where I saw the suggestion to cut the trace to make the output 3.3v.

    @zzing I noticed there that it changes the OUTPUT of the BLTouch to 3.3v, you still have to plug the Red wire for the servo into the 5V line of the probe plug.

    It does do the self test at power up, lowers and raises the pin just fine. Red light stays on after that, so no error conditions detected.

    M280 P64 S10

    M280 P64 S60

    Currently running 2.02rc3 and the latest web ui files.

  • administrators

    @kenny66 said in BLTouch on Duet 2 Maestro not responding:

    M280 P64 S60

    According to https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Software_setup_Duet_2_Maestro it should be S90 not S60.

    If the M280 P64 Sxx commands do nothing, that suggests that the servo control wire isn't correctly connected to the MOD pin of the Z probe connector.

    You don't need to cut the trace for 3.3V for the Maestro, but it does no harm if you do.

  • That was it. Sometimes you just don't know what to take a closer look at. I found a stray strand of wire just outside a dupont connector that was connecting the control wire to ground.

    Thanks for pointing me in the right direction. 🙂


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