(Duet 2 wifi) wifi wont connect when endstops are connected



  • Foolishly while Vin was powered and the board wired i plugged in my USB to configure wifi connection issues and have shorted the 3.3V line. Such that when end-stops are connected the wifi will not work (no blue light or connection), nor will (while power is off smh) USB connect, luckily USB C can handle whatever power the board was sending to my PC and i was able to disconnect after it gave me a warning. When the board alone is connected to USB the connection is just fine and all lights are flashing appropriately.

    Obviously, I should not run my machine without the end-stops connected. It cant be that connecting to USB while in power damages the board to this degree. Is there something I can do?



  • NC (Normally Closed) endstop switches should be wired to the "outer two" pins on a Duet 2 WIFi, labeled "Gnd" and "Stop".

    If instead they are wired to the adjacent pair "+3.3V" and "Gnd", and they are normally closed, they will drag down the 3.3V to the point the board will not respond to USB or WiFi.

    @naeemi said in (Duet 2 wifi) wifi wont connect when endstops are connected:

    luckily USB C can handle whatever power the board was sending to my PC and i was able to disconnect after it gave me a warning

    That warning is also symptomatic of incorrectly wired endstops. The board is trying to draw too much power through the USB, and the computer shuts this off and issues a warning.



  • Oh, and connecting USB while VIN is powered should be absolutely OK with very few exceptions.

    The one "gotcha" would be if the USB computer was at a significantly different ground potential than the power supply attached to VIN. Depending on a bunch of things about how that power supply is made, what PC and how its power works, etc, etc, this can, very rarely, damage something.

    In the real world, either everything tends to be plugged into the same (set of) mains outlets, or the computer is a Laptop.

    So, normally VIN and USB is just fine.

    Do you think you had an exception? That caused a problem?



  • @naeemi said in (Duet 2 wifi) wifi wont connect when endstops are connected:

    Obviously, I should not run my machine without the end-stops connected. It cant be that connecting to USB while in power damages the board to this degree. Is there something I can do?

    see
    https://duet3d.dozuki.com/Wiki/USB_ground_loops



  • @naeemi said in (Duet 2 wifi) wifi wont connect when endstops are connected:

    Obviously, I should not run my machine without the end-stops connected.

    You don't NEED endstops to run a machine; you can move the axes by hand to a specific position (eg corner of the bed) and set the position with G92. Alternatively, you could use motor stall homing if you have a hard stop at the end of each axis, at least for X and Y; see https://duet3d.dozuki.com/Wiki/Stall_detection_and_sensorless_homing. And use a probe rather than an endstop for Z. This, of course, depends on your machine layout.

    Ian



  • @Danal Thank you, that worked!


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