Smart Remote Power Control

  • To control the duet via PS-ON is nothing new.
    link text
    But to do this via a smart home actuator might be a more current option.

    While searching for an actuator I came across the Shelly 2.5
    I have chosen it because it brings its own web interface to control. And because it's not cloud bound by default.
    There is no nead for a smart home server. So it's already a good option out of the box.

    The goal was to be able to switch the printer in such a way that it cannot be accidentally switched off in the middle of printing. Also all loads should be switched off.
    The result is the following schematic. (Only the relevant area)


    The key is to switch the actuator parallel to the PS-ON relay output.
    I use an industrial relay with several channels, this has the advantage that one can switch a separated feedback channel once the duet is booted.
    Currently I have 3 channels in use. Power supply, feedback and the heating bed (220V).

    The following setting must be made in the switching channel of the Shelly.

    Set the button type to "Detached Switch".


    Set an "Auto Off" timer for that channel.
    With this setting the input switch (SW) can be queried separately.


    With this wiring and setting the printer only can be switched off by G-Code.
    Either out of the DWC or automatic at the end of printing.
    Of course, it also works via a hard-wired kill or main switch.


    When everything worked I have been thinking about how to make it more comfortable and to get acoustic feedback.
    The drama began seting up a homeserver starting to build a node red dashboard....
    To cut a long story short it ended with the integration of G-codes, video image and the activation/deactivation logic.
    Still work in progress...
    Demo Duet Remote.mp4


  • administrators

    Nice work. Is that industrial relay one that stays on even if the control signal drops (is that what the second path via the diode is giving you?)

    (btw added .mp4 upload)

  • @T3P3Tony
    This is a momentary relay.
    The secondary channel displays the status of the relay.
    In the node red flow it controls the button status (color and naming) and also deactivates the boot button once the duet is up.
    This is not absolutely necessary. But otherwise you can trigger the relay several times in a row. (From the Shelly's own UI that is still possible)
    With a slightly modified circuit it even would work with only one channel . To me with this wiring it seemed to be more logical and the relay was lying around unused.


    (btw added .mp4 upload)

    Still getting this error:


  • administrators

    can you try a refresh/reload on the broswer setting to test the mp4 upload pls.

  • @T3P3Tony
    No chance.....nor cleaning cash

  • I wasn't using a computer power supply, just a typical Meanwell DC unit.

    I wanted to be able to power my printers up/down so I got this:

    Controlled Power Outlets

    It has features I don't need but it has the local and remote power control that I wanted.

    I'm would imagine there are other similar units.